Hi Eyreel..
The one thing I searched and searched for when buying my system was a workable power supply (PSU), while on a
tight budget.
This forum page:
http://www.hardforum.com/showthread.php?t=792566
seemed to sum up what I was learning on the web...and in TechSpots' forum.
They do a ranking of not only what brand to look for,,,but also which to stay away from.....and also break down the decent ones into a few basic price ranges...everywhere from ultra-budget($30)----to ultra-expensive($200 on up).
If you bought your case
already then you can get a safe PSU for about $30-40 at NewEgg.com(keeping in mind the recommendations at that link..ie.. Sparkle-Fortron-Enermax etc..) There are a 'gazillion' inexpensive PSU makers out there....and besides being unsightly paperweights, they could potentially ruin your nice, new system.
If you
haven't bought your case yet, then I can only tell you what I ended up getting, which was a $59 Antec case (at NewEgg.com) with a genuine Antec 350W PSU included(which, unless you'll be adding extra hard-drives etc...will be plenty, even with a good VideoCard...and has plenty of amps at all voltages), the PSU fan is quiet, and the case is great, also.
On the 350W Antec I run:
1 Athlon64 3000+ (socket 939) with heatsink/fan...
1 hard-drive
1CD/RW drive
1 64mb Nvidea vid-card (don't ask why

)
1 128mb ATI 9600 Pro vid-card
1 MoBo
2 sticks 256 3200(400) DDR memory (in DUAL Channel)
3-4 USB things...(2 mice, joystick, USB FlashDrive etc,..)
I hope this helps...