The cloak and helm only required honored, so that's not so bad.
The personal guild rep cap is 3500 rep per week; this number is not affected by your current rep, your race, or your guild's level. The amount of rep you get is directly tied to how much guild experience (capped at 6.2 million per day until guild level 23) you supply, which itself is tied (in most cases) to how much experience you got/would have gotten had you not been at personal experience cap. I've got actual numbers for various things (my guild's been failing to cap since most of us hit exalted, which is incredibly aggravating since we're getting so close to 23 and losing the cap altogether), in case you're looking for the most time-effective ways to get rep/experience. Note that all these numbers are for a level 12+ guild; I dunno if Mr. Popularity affects this stuff but heirlooms do not.
The most effective way of getting guild experience/rep, if you have a good group of folks who are coordinated and can handle PvP, is to do rated battlegrounds. An RBG win in a guild group (8+) grants 700k guild experience, which is nearly 10% of the daily guild exp cap. For PvE, guild raids are equally effective (25s being better than 10s for this purpose)—the big difference is that you can run an unlimited number of rated battlegrounds, but there are only thirteen raid bosses currently available at level 85 (Argaloth, 2x in Throne, 4x in Bastion, 6x in BWD). Since I'm rep capped and they recently changed the numbers that guild raid kills give, I can't give rep amounts for these
Next most effective is running guild heroics; you need at least three people that are guilded in your run to get the experience/rep, but a full five is best since not only will your queues be instant, but you'll be getting the absolute most rep you can per boss. I don't
think these have to be randoms, and in fact if you're running dungeons just for rep it's best to avoid places like Throne of the Tides because Neptulon, for example, doesn't give guild experience/rep. I don't have full information here, but here's what I do have:
Heroic Vortex Pinnacle with 5 guildmates:
Grand Vizir Ertan - 113 guild rep - 46,000 guild experience
Altarius - 114 guild rep - 46,500 guild experience
Asaad - 114 guild rep - 46,500 guild experience
Heroic Shadowfang Keep with 4 guildmates: I wasn't tracking guild exp at this point, oops, but each of the bosses give 91 guild rep with the exception of Baron Silverlaine, who gave 91 guild rep
five times for a total of 455 guild rep. He summons the old worgen bosses from normal SFK, which is what gives the extra (I don't know if they've fixed this since I capped, I'll have to look on my warlock some day).
If you can't get guildmates to cooperate, questing is the only solo activity that gives guild rep (you cannot solo lower-level dungeons for guild rep and experience, since you won't have enough guildmates in the instance to count). The more experience the quest gives, the more guild experience and guild rep you get. There are some standard numbers across the board for dailies, though:
Profession Dailies: Stormwind/Orgrimmar Cooking, Fishing, and Jewelcrafting dailies all give 42-43 guild rep and 17,350 guild experience at level 85. Note that these dailies scale with level—Santi, who is level 82, only got 23-24 guild rep from the SW cooking/fishing dailies today (I would guess that's about 6k guild experience, though we're capped for another hour or two). Dalaran fishing dailies also give the level 85 quest amounts at 85, though the cooking dailies give slightly less (31-32 guild rep, 13012 guild exp for Convention at the Legerdemain)
Tol Barad: Tol Barad dailies—both on the peninsula and the "your faction controls the area so grats on Baradin Hold and quests access" quests—all give 42-43 guild rep and 17,350 guild experience. There should be six on the Peninsula and 6 on the, uh, "mainland." If your faction controls TB more than once a day, three of the dailies on the "mainland" randomize to one of three options (demons, ghosts, and crazy people!), so you could potentially get an additional six quests. TB dailies and profession dailies are the two best kinds of dailies for guild experience and rep (and gold, since at 85 all that personal experience gets turned into gold!)
World Event: There's a third type of "really good daily" and that's the dailies from world events. I haven't tried them all, but the valentine's day dailies gave 42-43 guild rep and 17,350 guild experience. I suspect other world event dailies would also give the maximum amount.
Wildhammer/Dragonmaw: Most of the Wildhammer/Dragonmaw dailies give 33-34 guild rep and 13,800 guild experience. The exception is "Warlorld Halthar is Back!" (Alliance) or "Bring Down the High Shaman" (Horde), which gives 42-43 rep and 17,250 guild exp (being an elite quest).
Uldum: There are only two dailies in Uldum, and they vary in quality. "Fire From The Sky" (the Bombardier daily) gives 26-27 rep and 10975 exp. "Thieving Little Pluckers," on the other hand, only gives 20 rep and 8,283 exp.
Therazane: Most of the Deepholm dailies give 26-27 rep and 10,975 experience. "The Restless Broodmother" and "Glop, Son of Glop" give more at 33-34 rep and 13,725 exp.
Argent Tournament: The AT dailies vary a bit in how much they give, but needless to say it's significantly less than level 85 dailies. Nevertheless, if you're working towards your mounts/minipets, AT dailies give 11-14 rep and 4,138-5,512 exp. Icecrown dailies seem to fall into that same range.
Netherwing/Misc: Netherwing dailies give 0-1 guild rep and 312-400 guild experience. "The Deadliest Trap Ever Laid" gives -slightly- more, based on personal exp amounts on Wowhead (I can't say how much at this time, needs more eggs!). Similarly, Skyguard and Quel'Danas dailies give the same or slightly less.
Don't forget, too, that regular quests will give guild exp and rep. The only problem with regular quests is that eventually, you run out! Curse you, unrenewable resource! *shakes fist*
Edit: OH GOD WORDS. Anyway, if you're interested in seeing how much guild experience you're getting, there are two ways to go about it:
1) In your guild tab, if you sort your roster by guild activity, you can see how much guild exp you've gained. Before they added in the (heavenly) marker for your weekly cap for rep in the guild "guild" tab, the only way to know you'd capped for the week without manually doing something that you know would give rep if you weren't would be to look at Guild Activity (weekly). It takes 1,575,002 guild experience to gain 3,500 guild rep. My guild leader yelled at me for changing my public note to that number (over "I'M DIED", *huff*)
2) Right-clicking on your chat tabs and going into settings, there's a "Guild Experience" option under "Other." I almost wish it were turned on by default since I keep forgetting to set it on alts, but not everybody wants to know, I suppose.
