If I could have my way, I'd definitely choose Sean (3rd Strike Sean, not crappy 2nd Gen Sean) but you have a good point, too many hadokens... BUT!!! Sean has no hadoken, shoryuken, or screw kick! He's even less hadoken than Dan, not an easy feat. (Just throwin' that out there)
including Ingrid would definitely be interesting, Urien would allow for a more ballanced illuminati character, Yang or Yun (one or the other, but not both) would help explore the story gap between Gen and Chun-Li, also Q would be really awesome.
(Characters that definitely WOULDN'T work)
Dudley; almost a perfect clone of Balrog
Any of the "Shin" characters; all clones
Necro; Dhalsim clone
(edit)
Remy: Guile Clone
I'm sure there are a few I missed...
(edit)
got it!
most of the 3rd strike characters would be hard to include, since they're mostly just crossbreeds of other characters, ie: (Necro = Dhalsim + Blanka)
