I actually haven't thought about that. I've been trying to branch out and get better with different characters.
For your lineup I'd have to say that, out of the characters given, you should go with Capcom, Akuma, and Gambit. I mean, this may be a little biased, as those three are the ones I'm best with out of the ones you said, but they balance each other out quite nicely. Although the computer recommends using Gambit's Melee attack as his assist, I say go for the ranged attack.
You see, this way you have three very fast, very agile fighters, one handling those doppledangers who jump around and use a lot of air attacks (Capcom), one for general purpose fighting, who's damage is enough to go up against tanks, but he can also hold his own against other street fighters and ranged fighters (Akuma), and a heavy ranged fighter with very, very fast tricky attacks, who can shift the momentum back when you're losing the battle very nicely. (Gambit.)
-Ryu from Street Fighter
Voted favourite N00B of 2008.