Latest generation chips use the least power, thus the least cooling needs for a given level of performance. Go for a 5xxx (5770 is fine) level card.
I personally use a Targus USB corporate standard keyboard (about $20)
Unless you need either an elaborate gaming keyboard OR a typist's dream clicking-switch board this will be fine. HP, Dell, M$oft and others also make good quality mainstream keyboards for reasonable prices.
For a mouse I always recommend a logitech laser. My wife and I both use G5s.