If graphical performance really isn't an issue, then just go with onboard. My work PC is a Dell GX620 which has a 945 chipset and I/G. I can watch DVDs, play a few games (low res, details off) and it runs office apps and Photoshop etc without problems. Why spend the extra cash? Also, any card you put in is likely to be actively cooled with a fan = noise. Just go with onboard
I wouldn't be too rough on the onboard Intel GMAX3000 graphics. It's quite a bit more advanced than previous onboard graphics from Intel due to it's unified shaders. It's nothing fantastic but the 3DMark06 scores I could find show it could possibly beat out THG's X1300PRO from the VGA charts depending on the resolution RegHardware used (they didn't indicate it).
The point being that the onboard GMAX3000 will be more than adequate for what the OP wants to do and at a fair price. I suspect they'll come out cheaper with the GMAX3000 than going with a GA-965P-S3 and an X1300 or 7300GS. Plus they still have the option of upgrading to a discrete card in the future.