kickback

I have a modded xbox that I plan on using as my dvd player. I have an HTDV tuner (Samsung SIR T-151). I want to be able to connect an IPOD. I have an old receiver that does not have an output for a subwoofer (so I am thinking of moving this to the bedroom). Would the DD5.1 with the THX Promedia 5.1 speakers work for my xbox, xbox as dvd player, HDTV STB, and Ipod? I really like the sound of these speakers and would rather go this route than Home Theater in a Box....I just need to know whether I am being stupid here. Finally, I see the 5.1 speakers for sale on ebay for 240 dollars. This seems to be too good to be true....was wondering what the klipsch policy on resellers/warranty is? Thanks in advance!