[cuiter23]

Listening at 10 feet away will automatically exclude desktop speakers so you will be looking at 5+ inch monitors (as others have already pointed out).
 
You could either get passive or active speakers. Some of the active speakers will come with a built-in DAC (Audioengine A5+).
 
Alternatively if you wanna be more fancy you could always go the passive route and buy a separate AMP and DAC. The KEF LS50 has been highly regarded around the community.

 

[cel4145]

His budget is $500, so KEF LS50s are definitely out.

 

[cuiter23]

Sorry wasn't reading carefully enough

 

[mrcjwagner]

Well, for this round anyhow I am going to try the Wavecrest Speakers and a Topping T30 amp -- will probably try it both RCA and USB, although I think my onboard soundcard is probably good enough so that USB won't make a big difference.  Thank you for all the advice.

 

[cel4145]

Come back and tell us how it sounds