Recently I came up with the idea to merge different arena fps together: I.e. before match start each player can select a 'class', which resembles the movement, health/armor system and weapons of his favorite game as accurately as possible.

Which game-styles/classes apart from the obvious ones (Quakes, UT, AG) would be interesting?
Is it feasible from a practical/technical point of view? Many fps games use some kind of quake engine anyways, so there should be some 'common ground'?