I will strongly recommend you audition other brands of loudspeakers before buying. I personally can't stand Def Tech's bipolar sound. And I'd sooner buy a subwoofer from a subwoofer company (Hsu Research, Velodyne, SVS) where my dollar will buy alot better performance.
As for power conditioning: I'd buy a generic panamax surge protector. Chu can give you a much better rundown on power conditioning in the "tweaking, connecting & accessories" forum area than anyone.
And don't spend more than $150 on cables (and that includes video cables)
BTW: Nice TV
