I haven't had any problems with NEC in the past, but I have a SAMSUNG CDrw/dvd-rom.
420 will be fine for PSU. I have a Antec 330watt truepower psu, with a AMD 64 3000, 6800, and 4 sticks of ram, 1hdd 1cd-rw/dvd-rom.
I recomend 2X seagate 80gb hdd. a dvd durner, NEC is a good make. Antec truepower 550watt (could get less power, and performance ram (Are you going to do alot of overclocking?) G. skill cheap ram (still $100 though) Well that comes to $389.49, so you may need to save up for that case.
Cisco CCNA, Comptia A+, 1/3 through CCNP