Need help/ support for Dell Dimension C521 Graphics/Video Card upgrade.

I know it's now a very  old system, but it is so dang upgradable, I'm just amazed.

I just had my 8600gt graphics fan fail. The card was PNY with a horrible fan, so I had to buy and change to a different fan, but the fan seems to be having some

problems. So I'm kind of tired of this card anyway, not that it's a bad card, it's an amazing card, but I'm just addicted to buying a better stuff on a crappy old system lol.

I have the 280watt power supply. Upgraded my CPU to 5200 AMD Athlon x2 processor 2.7Ghz 65W 1mb total L2 Cache. I also now seem to be able to run the 2 1gb 

sticks of ram at 800mhz, was probably because of BIOS update. 

So anyway this is about graphics card.

Is there anything better than 8600gt low profile card?

I looked up on newegg and found this http://www.newegg.com/Product/Product.aspx?Item=N82E16814102829

3 comments say that it works on C521, it's also an ATI Graphics card, I'm not too familiar with them though. 

Then there is this http://www.newegg.com/Product/Product.aspx?Item=N82E16814162030&cm_re=9600gt-_-14-162-030-_-Product

though it doesn't say that it's a low power one, but reviews say that it doesn't need a 6-pin connector, which would probably mean that it's low power.

Now, I'm just looking for a better graphics card than 8600gt, I don't think I will care much about low profile since I can just cut the case a bit/modify it by cutting the top

and removing the barrier that prevents using full size cards.  Just throw any card with PCI Express that's better than 8600gt and will work with my underrated 280watt 

power supply. 

P.S. Will appreciate any comments or just support. Thanks in advance.