isaborders1999 :
Bakua :
Go for the 1080, one powerful card is better than two weaker cards. You don't want to deal with SLI, it's a real hassle, it generates more heat output, consumes more power, and the drivers can be a mess.
Well if I sell the 970, how to I get the most value out of it, sell it now or wait till later?
It'll only go down, it's even decreasing now. With the prices of the new 10XX series, and the direction they're going in, it'd be wise to sell them now. Especially with the launch in a couple of days. Keep in mind that while people are selling them quickly, there are also potential buyers (because of the rapid decrease). If your current PC can handle it, I say go ahead and sell it. If you want, you can get approval from other Tom's Hardware members.