As I said, you may just want to get the Radeon. It's cheaper, in stock, and if you're planning to upgrade after getting back into the workforce, then why waste the money.
What is an issue is that there aren't enough games out there to take advantage of what the high-end cards do. PCs are also running into competition from consoles. At this point, consoles are mini-computers. They have 'Net access capabilities, portable hard drives, media players, etc. Heck, throw in a burner and a TV tuner and you might have a DVR that plays games. Games for PC aren't a hot market since you have consoles pulling a majority of the video gaming market.
As for ports, PCIe 2 and 3 are backwards compatible. So they will work in older PCIe slots. The only problem is that unless you upgrade your motherboard, you won't be able to take advantage of the benefits of newer PCIe standards.