Trying to pick a card for BF3, need advice. pwr source 300w

[fropo]

At first i was just gonna get the most powerful thing i can fit that's under $150 before rebates, but i've heard things about bottle necking here and there.so far i got these as candidates. I think i'll be glad with Medium, Medium-High settings. My room tends to get very hot, and i have no idea what the power supply is, but i don't expect much due to it being stock and all.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130625

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130661

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130770&nm_mc=OTC-FroogleNEW&cm_mmc=OTC-FroogleNEW-_-Video+Cards-_-EVGA-_-14130770

http://www.newegg.com/Product/Product.aspx?Item=N82E16814130750&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-RSSDailyDeals-_-na-_-na&AID=10521304&PID=4176827&SID=11tiiiy91hawz

i;m not very good finding out my specs, but i got this using pc wizard 2010.

Mainboard : Gateway RS780
Chipset : AMD 780G
Processor : AMD Phenom II X4 810 @ 2600MHz
Physical Memory : 8192MB (4 x 2048 DDR2-SDRAM )
Video Card : ATI Radeon HD 3200 Graphics
Monitor Type : Gateway HX2000 - 20 inches
Network Card : Marvell Semiconductor (Was: Galileo Technology Yukon 88E8071 PCIe Gigabit Ethernet Controller
Network Card : Realtek Semiconductor
Operating System : Windows 7 Home Premium Home Edition Media Center 6.01.7601 Service Pack 1 (64-bit)
DirectX : Version 11.00
Screen resolution is 1600X900
power source is 300w

everything is pretty much default right now.
i'm also taking suggestions about other components.
if you need other information let me know Because honestly i have just about no idea about what is relevant and what is not.

 

[Deemo13]

Given the computer is pretty much how you bought it, you are definitely not going to be able to run any of those cards on the power supply that I am assuming is in there. There is probably about a 300W PSU, which is most likely just about enough for a Radeon HD7750

 

[fropo]

is that card any good?

 

[Deemo13]

Either way, its going to be the best you can do without upgrading the power supply.

Its a great card. Should run BF3 on medium-ish.

 

[fropo]

coming from console, i'm happy with that, and the price is not that bad.
thanks.