Need a video card compatible with ASRock 775Dual-VSTA motherboard

I bought this motherboard (http://www.asrock.com/mb/overview.asp?Model=775Dual-VSTA&s=775) last year so that I could keep most of my current hardware, but upgrade my old CPU. Now, I'm sort of at the same stage again (ie, not able to spend too much, but would like to upgrade my video card).

I'm currently using an older ATI 9600xt (PowerColor) video card. After doing a little reading, I'm thinking something along the lines of an ATI HD 2600xt would be a suitable upgrade. The problem comes with what I'm able to use in my particular motherboard. The PCI-E slot on this board isn't an x16, and there's a limited number of cards listed as compatible on the manufacturer's website (http://www.asrock.com/mb/vga.asp?Model=775Dual-VSTA&s=775). The only ATI HD 2600xt card listed, is the Gigabyte GV-RX26T256HP-B, which I can't seem to find. It's listed on Gigabyte's website (http://www.gigabyte.com.tw/Products/VGA/Products_Overview.aspx?ProductID=2590), but not with any online stores that I can find (based in the US, anyway).

I suppose I could go with an AGP version, but it's not something I could continue using once I do get a new motherboard (which I'm not keen on doing right now due to my older DDR1 RAM). Most of the AGP cards seem more expensive than their PCI-E counterparts as well.

Anyone know of an online store that carries the Gigabyte GV-RX26T256HP-B? Or some other compatible video card with similar price/performance?