The best way to find out what sort of memory you need is to go to http://www.crucial.com (using IE), and do the system scan on the front page.
There is a chance that it won't find the memory speed or the motherboard manufacturer, in which case, post the whole output of the scan, and we might be able to help.
Also try <a href="http://www.majorgeeks.com/download181.html">Aida32</a>. That should give you the model of motherboard too.


As for the graphics card, the 7600GT is a very nice card; not as nice as a 7950GTX, but adequate for today. It's not overly powerful, but then again, you're not paying a huge amount for it. It's likely to be perfectly adequate for whatever you want to do at this stage; my 6600GT runs Oblivion at medium quality, with a res of 1280x1024 with no problems.
You'll want to be aware that the card isn't going to last much longer with the release of DirectX10, and the inevitable migration of software producers to the new standard. That auction states that the card is built for Vista - It is not built for Vista; if it was, it would have DirectX10 support.
Also be aware that Palits are some of the cheapest GPUs I've seen; I've never used them though, so I don't know how good the quality is.

Really the main thing that I'd consider would be the lifetime of the card. I make a lot of noise about being anti-Windows, but in reality, I keep a Vista partition for my games, and with games there comes DirectX. OpenGL is always there, but the majority of game developers are using only DirectX and DirectX10 is the next step, so don't want to shell out for a GeForce7, since they don't support DirectX10, and I don't want to shell out for an 8800GTX (one of the few cards that do support it), since they're like, a grand.
I'm going to hold off until GeForce8s come down a little in price and get an 8800.