Ultra low end graphics card for playing old titles.

At my desk sits a 6+ year old core2duo 2.1ghz sff desktop and it does almost everything I could possibly need. It plays games, browses 't net, edits photos etc.

Issue is there are a few games I's quite like to play that need something a bit more beefy than the onboard intel graphics can handle. Issue is that the gpu needs to be low profile and low power.

The choices are.

R7 240 2gb ddr3 - 40 quid
gt 730 2gb ddr3 64bit - 40 quid
gt 730 1gb gddr5 64bit - 48 quid.

All of which will run every game I want to play in 1280x1024 at high frame rates.

The question is, which one do I buy.... all have advantages and disadvantages over each other.

Other than buying the 240 as it's the lower power or the 730 gddr5 as it's the fastest. Can anyone else throw anything else into the mix that might help? Ebay is also useless and they seam to go for more 2nd hand than new :P

note : my psu is only 180w or I'd just buy a 750ti and be done with it, but cant.