My current PSU is 230w, i'm building an almost completely new pc soon, and wanted to buy a new one, but i know nothing about psu's, what's good, what's not etc, i was gonna get an antec one but there expensive, someone recommended enermax but i think there expensive too and dunno which one and if there any good, i found a cheap q-tec that looked decent called Q-Tec PSU 400W Dual Fan Gold, but can't find a review and dunno if it's any good, so if someone could help, i'd appreciate it :)

An entire case w/PSU is usually cheaper than just buying a PSU alone. Tom's Hardware recently did some testing of PSUs...

http://www6.tomshardware.com/howto/20021021/index.html

I highly recommend the Enermax 350W if you've got enough cash. As far power supplies go, I only trust Antec/Enermax. Here's a guide to help you out:

http://firingsquad.gamers.com/guides/power_supply/

I found a 400w Power supply from tigerdirect for $30 bucks. I origonally put this in an old computer cause i thought it would be crap, but it turnes out it's great! Look for a good deal on ebay or something.