Upgrading to 9800gtx, need some help

I'm looking to upgrade to the 9800gtx, but since this will really be the first time I install a new part in my PC, I need some help with how to go about it.

This is my system atm:

Gateway DX 4200 09
Vista 64 bit
AMD Phenom X4 9100e / 1.8 GHz (a bit slow, i know)
4GB ram
ATI Radeon HD 3200 Graphics
300W Power Supply

So along with the graphics card, i'll obviously have to get a decent power supply.

This is the GC i'm considering:
http://shop2.frys.com/product/5806 [...] N_RSLT_PG]

and the PS:
http://shop2.frys.com/product/5503 [...] N_RSLT_PG]

Amperage on the 12V+ rails: 22A, 22A, 25A.

So i guess the question i have is: Will this PS and GC work well on my system? And also, is there anything that might work better for a similar price?

Thanks a lot

Power supply: Probably, but I can't say for sure, as I don't know much about your case's dimensions.

Graphics card: Decent card, but given that you already have ATI drivers and are concerned about power consumption, have you considered the HD 4770 or maybe even the HD 4670? It performs at a similar level and consumes less power.

http://www.techspot.com/review/163 [...] age12.html

Processor: Concerns me a bit, hence my "downgraded" graphics card advice above.

After reading up on the 4770, I am pretty impressed, and will most likely go with it instead of the 9800gtx. Thanks for the suggestion

Since this card consumes less power, and I won't upgrade anytime soon, can anybody recommend a good 450-550W power supply (the 650W i picked for the 9800gtx seems a bit excessive)