The motherboard has a pci-e x16 slot, so it's good to go for the video card. The no-name 500 watt PSU might or might not have what it takes. It technically meets the minimum specifications, but it's hard to tell how good the quality is and most big manufacturers tend to slip in pretty underwhelming PSUs. If you have the cash to spend on a 670, another $60 on a quality brand name PSU would be a good investment.
A lot of Seasonic PSUs are actually FSP-built anyway. A lot of people don't realise but only one or two Corsair models are made by Seasonic. All of XFXs models are. Or Silverpower SP-Sxxx / SP-SxxxM / SP-SS lines, PC Power & Cooling Silencer series and Silencer Mk III series.
That's true, sam, but that particular FSP unit is of old design, lacking power on 12V rails.
I'd suggest upgrading the power supply in addition to the graphics card. Get a decent 500-600 watt unit from Antec, Corsair, FSP, Seasonic or XFX. Other than that, check out whether your PC case is large enough.