Punduke, the PSU is just as (if not more so) important than other major components in a system. After all, the PSU is what supplies the necessary power to ALL the system components. If it is supplying crap to your components, guess how they will respond...? You might want to review this old thread I posted a while back regarding PSUs.
Power Supply F.A.Q. - September 2007
Unless you are building a very demanding system (quad core processor, multiple drives, SLI/Crossfire) you will find any of the PSUs listed below as acceptable, adequate, and sufficient for your build. You don't need a $200+ PSU to run 95% of the systems in use today. However you also don't want to use a $50 pos PSU either. That is just asking to get your expensive components damaged due to bad voltage/amperage feeds. As a rule of thumb, a good PSU for a new high power system (dual/quad core CPU/single GPU), will run ~$100US. Also, I always recommend a PSU have active PFC (power factor correction) to ensure that the feeds are clean and regulated.
Newegg.com - PC Power & Cooling S61EPS 610W Continuous @ 40°C EPS12V Power Supply 100 - 240 V UL, cUL, CE, CB, TUV - Power Supplies
$89.99 after rebate
Newegg.com - OCZ GameXStream OCZ700GXSSLI 700W ATX12V Power Supply 100 - 240 V - Power Supplies
$94.99 after rebate
Newegg.com - CORSAIR CMPSU-650TX 650W ATX12V / EPS12V Power Supply 100 - 240 V UL, CE, CB, TUV, FCC, CCC - Power Supplies
$99.99 after rebate
As an aside, I prefer to install floppy drives in all my systems. They are still useful for flashing the BIOS if nothing else.
