350-400W is plenty. The best way to check is to go to intel's web site and see what power supplies are recommended with your particular CPU. Make sure the 5 VSB is rated at least 1.5A or you will have trouble with ACPI if you board is so equipped.
Dear god, do yourself a favor and upgrade to 256Mb Rdram, you will see a huge increase over 128mb. Don't forget, you have to get pairs of rdr, they work in a dual channel configuartion. Yes, an enermax 350 watts is sufficient. Looks good.
"When there's a will, there's a way."
Yes, 350W for an Enermax, or 400W for an Antec/Generic (if the generic even works at the proper voltage).
<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>
if your going to build a decent computer i <b>STRONGLY</b> reccomend you get at least 256Mb of ram.