Best Home Theater sub or subs for a large room

I am building a dedicated large home theater. The dimensions are going to be 32 feet by 25 feet. There will be three levels of seating. The back of the room will have an 8 foot ceiling. The front will have an 11 foot ceiling.

How many subs?
Which ones are recommended?
Where would you place them?

I would like to spend less than $2500 for the sub or subs.

Any help would be greatly appreciated.

The room is modeled after a theater at Bradfordwells.com. See:
http://www.bradfordwells.com/theater2.html

Cheers!