1 Def Tech Supercube II vs 2 Def Tech ProSub 200TL

What subwoofer set up should I use for my surround sound?

1 Def Tech Supercube II or 2 Def Tech ProSub 200TL

Receiver: Sony STR-DN1000
Fronts: Def Tech BP-30
Center: Def Tech C/L/R 2002
Rear: Def Tech BP2X
DVD: Sony Blu-Ray BDP-S550
Comcast HDTV
TV: Sony 60" LCD
What is your room size?
What is your budget?
The supercube 2 is a 8 inch 1250 watt sub for $899 new.
The Pro Sub 200 is a 12 inch 250 watt sub, not sure price.
My room size is 14 x 22 and I have 2 Supercube Reference Subs and they sound great. They run $1899 each new.
Room size is 27 x 14 in a basement with a 7 foot ceiling.

Budget is about $600 so I can buy either setup.
I have the pro sub 200 left over from a system of long ago. It is very weak. I am not an authority on subs but I would think 1250 watts out of an 8 inch would move more air than 2 12 inch subs pushing 250 watts. But I may be wrong. Good luck.