I suppose the question becomes is this possible and if so is it affordable? I’m looking at picking up an S from Ebay or the like but only if I can get a 9700; do any of you know if there’s a way to do this? Thanks.

This will not be an easy or cheap thing to do. You can’t simply buy the chip. It’s believed to be soldered onto the motherboard so you’ll need to order a new motherboard in order to upgrade the video.