GPU upgrade for 300W PSU?

[YoungTechGeek]

I have a 300W PSU and I would like to know what graphics cards I can buy within that range that I could do some gaming on - like Battlefield 3 or F1 2012. My Budget is £40-£50. I don't mind second hand ones
My system Specs are: HP p6300uk
AMD Athlon II X2 215 (Dual core, 2.7 GHz)
3.00GB Ram (apparently only 2.75GB is usable)
Nvidia Geforce 6150 SE Nforce 430 256mb - Terrible I know!
WD 500GB HDD
300W PSU

Here are pictures of my motherboard to give you an idea of how much room I have to play with: http://flic.kr/ps/2t4aLu

I saw a radeon HD 6670 for sale. Would this be compatible?

 

[clutchc]

I can't make out the full name on the MB, but if this is it... http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&dlc=en&docname=c01925534#N300
...then you can use the HD 6670. In fact, if your 300W PSU is of good quality, you can go with the HD 7750.