Will my PC handle this card?

[zerstorenser]

Greetings everybody.
My PC is horrible for gaming, today I was in a second hand game/pc store (reliable, bought there before) and I saw the following card very cheap 'GeForce GTX 260 896MB'.
I also saw another card even cheaper, 'Radeon HD 4670 1GB'.
I know that both cards, despite the GTX 260 being the obvious winner, are much better than my current, (brace yourselves) 8400gs...
I would buy the GTX 260 in a second, but I am worried that my PC cannot handle it in terms of power supply or something, (I have seen threads about this kind of thing). I have no idea about any of this and if somebody could please tell me how to list this information to you, I will and then you could tell me whether or not either card could be supported by my current PC.

Thank you.

 

[GreenDutchAlien]

Hi.
Open your case and look for a sticker on the side of your power supply and write down everything you see according to the power.

 

[zerstorenser]

Ok it's by 'Bestec' Model: ATX-300-127 Rev:CCR
INPUT: 100-127V-7A, 200-240V-4A 50/60Hz
Theres a bunch of random OUTPUT stuff which doesn't make too much sense.
Then, at the bottom
'+5V & + 3.3V 180W MAX, +5V & +12V 288W MAX

 

[zerstorenser]

OH and on the output thing which didn't make too much sense it did also say '300W MAX', I missed that, sorry.

 

[zerstorenser]

Maybe I should also mention I upgraded from 1GB DDR2 ram to 3GB DDR2 ram

 

[GreenDutchAlien]

Forget the 260, it needs a lot more power than that. http://www.tomshardware.co.uk/forum/312770-10-will-support-nvidia-geforce
The 4670 would be possible though.
Didn't find a 6670 second hand by any chance ?