I did a lot of thinking yesterday and today.
It occurred to me the likely reason why my TV is stuck @ 2160 @ 30hz is because of HDMI 1.4. With HDMI 2.0, I can set the PC's output to whatever I want and the TV will display 2160p @ 60hz. I can go to 2160p today, but it is stuck at 30hz. So even if I have to go down to 1440p that will certainly be an upgrade over the 1080p. This made making a decision around an upgrade even more compelling.
I had to make a few assumptions assuming I sold whatever I bought to upgrade to Pascal. This has to take in account their values/cost today and what it would be when Pascal launches.
Assumption 1 - The 290Xs will be worth $150/ea at Pascal's launch and worth $200/ea today.
Assumption 2 - The 980 will be worth about $50 more than 290X when I sell, so $200/each at Pascal launch.
Assumption 3 - The 980Ti is worth $100 more than a 980 at Pascal launch @ $300. I looked up what 780Tis go for and they are still $300+ for some reason, so I thought this was reasonable.
Who knows what the exact values will be, but I think this is close enough to help make a decision. As long as their differences are similar the cost to me will be the same. After finding out what each product will cost me and estimated resale, this is the result.
I really want a 980 Ti SLI, who wouldn't? But in reality it is just too expensive to justify.
Then it was between the 980 SLI & 980 Ti. After looking up multiple reviews, the thing that stood out to me was the highly variable scaling. Some games are very poor at it, some games are very good at it. The benefit to minimum frame rates was not quite as high as expected.
Still a tough choice, I decided to go with the less expensive option of a single 980 Ti. I chose the Zotac Amp Extreme which I found for a pretty good price ($570 total after taxes & offers). It has one of the highest factory OCs with a high grade air cooler. It is a custom design and has a backplate which surprisingly isn't standard for this card. Hopefully with a better binning and bigger heatsink, I can get 1500mhz out of it.
Anyway, looking forward to setting up the 980 Ti. I should get it on Monday. If Pascal can bring me single GPU 4k gaming, I'll make another leap then. Not so sure we'll see it with baby Pascal, but I have high hopes for Big Pascal.
Thanks everyone for the help.