Uhhh, it's nice to say, "go with whoever you look like", but I think that in general it's best to go with your favorite character, and then if you look like them it's a happy bonus. Some characters have got some crazy proportions and are impossible to perfectly emuluate, so try your hardest being as accurate as you can to a character you're fond of. ~
Oh, and if it's a height issue you guyys could experiment with angles when taking photographs and maybe wear platform shoes or something. For our Gurren Lagann group, Shay's slightly taller than me, but in the show Yoko is taller than Nia so I'll have to find some good platform base boots, or something like that to compensate.
Good luck! =)