If you could get a single book containing, 2 new classes, several archetypes, a dozen or so new spells and a similar number of items, and some setting details published what sorts of classes and spells would you pick?
My book would be based around a gladiatorial arena.
The first class would specialize in dirty fighting with exotic weapons as I think a class designed almost purely around maneuvers would be very interesting. I might also see if there is a way to give them some 4DoS interaction as a test to see if it's really that bad on a martial class.
To accompany it I'd take a crack at a Con-based martial class that specializes in latching onto a foe and being impossible to remove until they choose to let go. Like a Greco-Roman-style wrestler but far more lethal and nasty.
The spells would be based around creating spectacle and changing the arena's terrain to favor you and your allies.
The items would include weapons for our dirty fighter as well as anything else on theme for the arena.
I'd try to get rules for fighting for show. Such as called shots that lead to exaggerated injuries to represent the showmanship of the pits. These could also serve as added content for people that would like this sort of thing for use in a normal campaign.
What would you ask for?