Mini HT via PC.

I just purchased my friends three year old, overclocked gaming PC that also has an excellent video and audio card. I'd like to connect a Rotel pre and amp to power four Ratshack LX5's with 360 degree Lineum tweeter and a sub.

He said it would be overkill and that I should buy a Logitec surround system and use the Rotel pair as a mini system. Whaddya think?