antec is really good. i have the SL models and they work great. i heard that one of the best power supplies for the antec line is the antec neopower one. it outputs like 480watts i believe.
350watts should be the bare minimum but 400watts is good. i have a SL350watts antec power supply that came with my antec case its enough to power my system i have no stability issues. my config is athlon xp 2500+, asus A7N8x-E, 512megs pc3200, geforce 6800GT, 2hdds, 2 opticals, and i never have a problem.
here is a power supply roundup from xbitlabs:
http://www.xbitlabs.com/articles/other/ ... l-psu.html
check it out. other good brands to get are OCZ, pcpowercooling, and even sparkle.