Looking for feedback on 3v3.

Tonight will be my first night multi-logging. I already have a 70 hunter, which is what I'm building my trio around. I definitely want a priest, (wish I could defect my UD priest to Alliance..) which plays well with hunter from I've read. From the same threads a Warlock will play well with both as a duo, which is a class I've always wanted to play but never got around to leveling. My ultimate goal is to have a 3v3 team by myself.
Now my question is will these three characters fit well together in 3v3 arena while multi-boxing? I don't want to get a Lock/SPriest duo to 70 and end up being stuck having to level up a new character that will play together better in an arena. I've seen all three inside of multi-boxed 5v5 builds, so I'm assuming I'll be fine; I'm just a multi-boxing newb and would like a bit of pointing in the right direction if it is somehow a completely horrible grouping. The other consideration I'm trying to keep in mind is to have 2 different classes aside from hunter in the case I decide to stop multi-boxing for some reason after I finish leveling, since this is my first attempt.
Thank you for your input/time.

3v3 "synergy" is tough with a multiboxer. With 3 players, you're at the point where you can't instagib a player down with DPS... yet you're at a distinct disadvantage when it comes to movement (ie all players "follow" a main). The best PVP combos involve 4 characters with extreme DPS, and a separate person controlling the healer. If you can't swing 4 accounts, doing a 3v3 with a separate person healing would be better. Unless ofcourse you just want to lose 10 games for welfare epix :)

Much appreciated. Maybe I should just go Sham x4 to get used to everything and just level a full group later to mix and match. Seems as if I would have more fun that way. Thanks a bunch.

I have been pretty successful running a 3v3 multi-box team on the TTR. The team is an Elemental Shaman + 2 Destro Warlocks. Lots of DPS, silences, fears, and a healer when needed.