I have built 2 comps using this ECS board. One is is using a Sparkle 300w (around $27) from newegg i believe. It has 1 cdrw, 1 dvd rom, 1 20gig hd, 2 fans and a matrox agp vid card,1x 256mb sdram, xp1800+. It is running stable and have not had any crashes for about a month now.
The Other computer is running with an onlder Wintop 250w power supply. I do not know anything about this PSU. It was pulled from my old P3 500mhz machine. The rig has 1 dvd rom, 1 20gig HD, 2 fans, 1 matrox agp card, 2x 128mb sdram, xp18000+. So far it has been stable and no crashes or wierd bios, cmos, problems so far (crossing fingers).
I am assuming that unless you are putting 4 HD's, 3 cdrom drives, overclocking etc., a 300w antec, sparkle or enermax will suffice. HOWEVER, if i were you, i'd go with a higher powered PSU for future expansions, a 400w or 450w would be a good bet.