Thanks for all the responses. I ended up purchasing two EP800. I got one from B-Stock and the other from the Factory Outlet. I didn't try to negotiate a deal for two SVS PB-16 Ultras so I don't know what it would have cost me, but I figure I saved myself around $2000 by ordering the EP800s.

As much as I would have liked to order both and audition them, it would have been too much hassle and my wife likely would have thought I'd gone bonkers. Considering the only experience I have with a subwoofer is the EP500, and it's been a favourable one, I figure I'll be more than happy with the EP800s.

The only concern is that it might limit my placement options due to their height. The SVS subs would have been lower than my front projection screen so I could have moved them closer together and under the screen. With the EP800s, I'll have to keep them outside the screen. Or move them elsewhere in the room.

Regardless, they should work just fine. And they've already shipped so it's pretty much a done deal!