Cool, Asus P5QL-EM is a good option for Intel, the onboard graphics (X4500) isn't too bad, and it supports HD resolution.
AMD mobos give better value than Intel most of the time. Check out the Asus M4N78 Pro, similarly priced (±R950) to the Asus P5QL-EM and has more features.
AMD CPU wise you could save quite a bit by getting their entry-level quad, the Athlon X4 620 at ±R1100 (although the Intel equivalent (Q8200) would outperform it).
Don't really know much about specifically silent PSUs (maybe speak to LFX). But the Vantecs are great - cheap, good quality, and they have a "silent" 135mm fan which I've only ever heard with my head in the case.

I see the
Vantec ION2+C 460watt (perfect for your system) has dropped in price to ±R370 - amazing!