concerning power supply?

I just bought a new video card (http://www.newegg.com/Product/Product.aspx?Item=N82E16814133204), but my gateway Gt5476E only has the minimum power supply (300W). I have not installed the video card yet but since I will be playing mid level games I think I should upgrade the power supply? What do I need to consider when upgrading the power supply? I need help in getting the correct power supply since I don't want to damage any hardware. Here are some specs (if they help at all): AMD Athlon 64 5000+ Processor, 2GB of memory, MCP61PM2MA AM2 uATX Motherboard.

Thanks

 

The PSU is the worst place to go cheap in my opinion. But this one should be a little better than the stock PSU http://www.newegg.com/Product/Product.aspx?Item=N82E16817153023

That is a pretty good price, I have used simular PSU's on low end computers with no problems. I am a big fan of the OCZ PSU's http://www.newegg.com/Product/Produ...=2010320058+50001550&name=OCZ+Technology,+Inc.

Good luck!

E