hey all, I'm looking to upgrade a few things and thought i'de check around for some advice beforehand =)

Firstly i'm looking into upgrading my Processor my current Processor is
The system is a Compaq Presario SR1950NX

AMD Athlon 64 3800+ 2.4GHz
Running on 32bit Vista home premium (will ideally be going 64bit very soon)
Motherboard
Manufacturer: Asus
Motherboard Name: A8N-LA
HP/Compaq motherboard name: Nagami2-GL8E
RAM: 2202 MB (2.5Gig installed)
Video: GeForce 7600 PCIe 512Mb

I'm looking for an affordable proccessor in the 2.8GHz-3GHzRange that would be compatible with this system. I'll likely be using www.tigerdirect.com as my retailer for parts so any direct links would be much apreciated!

Secondly

I'm looking to pick up a GeForce 8800 GT (saw one listed for $50!) and my system only runs a 300watt power supply, would it be required that i upgrade my powersupply in order to run this video card? I know several people that run it on 400 and 500watt power supplies and have no trouble or performance loss, I'm hoping that i can get away with the same on a 300watt supply.

I'll be watching the thread for a bit hoping for some quick replies, thanks you in advance!