Gtx 970 Sli vs Gtx 980 (sli?)

Solution
If I was given that choice, I would choose 970 SLI immediately.

However, that decision would largely depend on your resolution, and the rest of your rig.
probably a better deal to get 970sli though even 1 will do great at 1080p.. for 970sli i would say go for 1440p for some great quality and frame rates.. can of course go higher just depends on the standard you have