i like the klipsch 4.1s, but thats only because i prefer less and more controlled bass. both are great though. best for the price? did you say your brother listens to music? for music, 4.1 is probably overkill, and quality might be degraded, you can look at the aego 2 or the swans diva m200 at that price range for PC, will kill either choice. also check out the cambridge soundworks PC systems, i would guess they are the best PC speakers have to offer, although i havent heard them (im into headphones). for $400 for 2.1 id guess they are quite good. just a suggestion thats all. i really like the klipsch 4.1s though, and i used to have the z560s and also thoroughly enjoyed them until i came to realization that my bass-headedness was not the way to go.
as for looks, i prefer the elegant, but conservative look of the black klipschs. sweeeeet.