Naw, HTPC questions go slow here. I don't build HTPC either, but do use a couple of old PCs to time shift TV.
1. IF HTPC only drop to 4GB mem. If anything else keep the 4gb, it's cheap.
2. Google AMD TRINITY and see if you want to wait a few weeks. same perf, 1/2 the power or more performance at same power. Should move price points a bit.
3. A6 comes with Heatsink and Fan included. Are you trying for a quieter HSF with the Scythe Kozuti ?
4. Why the case fans vs. letting PSU pull out the heat ?
5. Very big PSU for this system, a unit with 300W would be more efficient