PSU: 400w 22a on +12v's or better. You should get a 450-550W if you want some headroom for future gpu upgrades. If that's all you'll run until the next major overhaul, then a 450w is fine. Corsair is a good brand. Earthwatts is another.
CPU HSF: The Zalman 9x00 is whisper quiet if you don't overclock. If you do, look at xigmatek hdt-s1283.
GPU HSF: See above & consider the GTS512 which has a dual-slot cooling fan. Quieter & cooler & faster. $40 extra is a no brainer cuz you probably spend $40 on a good GPU cooler.
KB/Mouse: Personal preference. I prefer Microsoft for their ergonomic non-cramp-inducing designs & ultra super mega tiny drivers. The scroll wheel is smooth as silk.