I'm running fairly large, inefficient speakers with them, but for your purposes one amp would work fine. It is very solidly built, and has a beast of a traffo in it.
Since it's a desktop system, I'd also consider the Zamp. I have two (run bridged) and have been really happy with them. The smaller footprint might be nice.
I doubt the fully balanced system would be a large audible gain.
http://www.parasound.com/zamp-v3.php