I agree with Mongoose here, Luffy. You need something comic book/fantasy-like for this. It'd have to be like an action movie or fighting video game, with wacky occupations and backgrounds. Something like this:
Class type (highest to lowest in terms of power/skills):
Athlete (Boxer/Wrestler, Gymnast, Tennis Player, Runner).
Bimbo type (Supermodel, Pornstar, Playmate/Magazine Model)
Spy/Covert Ops type (Secret Agent/Assassin, Soldier, Hacker)
Martial Artist (Kung Fu Master, Ninja, Trainee)
Magic (Sorceress, Witch, Nun)
School (Headmistress, Teacher, Schoolgirl)
Outdoorsy (Amazon, Hunter/Bounty Hunter, Cowgirl, Safari Girl)
Power (Businesswoman, Mobster, Heiress)
etc, so on and so forth.
King=Most valuable piece. Not necessarily the toughest. The Power pieces should go here. A Businesswoman conducts efforts against another King (General/Politician/Mobster/Rival Businesswoman/etc).
Queen=The toughest piece. 1st tier. Could be a Sorceress vs. Superheroine vs. Legendary Swordfighter.
Rook=2nd tier fighter but not necessarily the most conventional occupation. I am thinking Secret Agent vs. Kung Fu Master.
Bishop=Someone with authority. A 2nd tier fighter but not necessarily a strong fighter. A more conventional occupation. Nun vs. Teacher/Headmistress vs. Celebrity/Heiress/Athlete (could be funny to cast a real celeb or athlete).
Knight=Soldier types. 3rd tier. Amazon vs. Soldier vs. Mobster/Gangster vs. Ninja vs. Witch vs. Boxer
Pawns=Military or Police Units/Security Guards/Models/Actresses/Martial Arts Trainees/etc
Of course, height, weight, appearances all depend on the individual character themselves. It would be better to have some unpredictability. Still, when a cornered King is trapped against multiple Rooks, the King will obviously be unable to fight and thus, back into a corner and cry. A checkmate scene might also be Rated X.....
Epilogue should be all the pieces of the losing team captured, tied up, and humiliated in a confined area (after all, the winner takes the pieces after knocking them out of play).