what speakers to use?

I think you would find the Paradigm Studio Reference series a major step up from Def Tech at little difference in cost. And there are many other excellent possibilities that I'm sure others will suggest.

Have fun choosing. Let us know what you decide.

will

Totem Dreamcatcher 5.1 looks promising:

http://www.totemacoustic.com/NewFiles/dreamcatcher.html#Anchor--------56664

PSB Stratus Gold i speakers. Floor-standing tower. Know of a great deal on a pair. These speakers are a class B stereophile rcommended speaker. Top-notch quality and performance. You simply cannot go wrong with these!
Give em a listen!!!!

Akio76 - I second the PSB Stratus Gold recommendation for your application. Nope, I'm not a PSB dealer.