Need help with video card upgrade

I'm sorry if there's already a topic similar to this, i've searched everywhere, but i didn't find a case like mine. I have a Dell OptiPlex GX240 desktop tower case (http://www.productwiki.com/upload/images/dell_gx240.jpg) with a Dell OptiPlex GX260 motherboard and the PSU is of 250W.  As you know it has an Intel Graphics Integrated card that it's pretty simple, just for office stuff.

I want to make it a little upgrade, don't want to spend a lot of money on a pc that is not really meant for gaming, but i do want it to run some games like Guild Wars, World of Warcraft, etc on at least it's minimun requirements. So as far as I'm concerned, the Dell OptiPlex GX260 motherboard has 1 AGP slot and 2 PCI slots, most issues with upgrading the video card on that motherboard is that is has to be low profile or that the PSU is too low and can damage the motherboard, but I think that's not a problem  for me (please tell me if i'm wrong).

I would like to know which video cards I could get on my pc (i know my AGP slot is a 1.5 version and is 4x, about the pci i don't know any specs, if you need to know anything else tell me how to do it and I'll try to give you the info). I don't want to spend more than 60 dollars on the video card, I just want it to run Guild Wars without a problem (Minumun requirements: ATI Radeon 8500 or GeForce 3 Series Video Card with 64MB of VRAM). People have told me GeForce FX 5200 or GeForce 6200 are the best options, but I want to be totally sure so I don't waste my money on something I won't use at all. I hope you can help me or assist me with any guide I so I could find one video card my pc can handle.

The Video Card I have in mind is the Sparkle GeForce FX5200 Series - SF8834-DT (http://www.sparkle.com.tw/product_detail.asp?id=12&sub_id=23)