Crossfire isn't worth the issues 2 GPUs bring, though you could simply go the less expensive route and get an R9 fury which is about 100 bucks less than the 980ti.
The fury should also do a bit better with time, especially if they unlock the overclocking on it, assuming it's a software issue. Though the 980ti will do better with an overclock on it.
I vote for a good aftermarket 980ti (Gigabyte/EVGA/etc.) OR if you can, wait until next year with Nvidia's Pascal release, you may be able to score better pricing or a Pascal card with HBM 2.
If you want to go AMD, a Fury (non-x) is a solid solid choice as well. A bit cheaper and has HBM already.
Thanks guys , I think I might save up for a 980 ti, I'm hoping it will heat up my system less.... although it`s not a bad idea to wait till next year and see what Nvidia is offering with Pascal as it looks very promising.
If you're worried about heat even with a 980ti, check out the EVGA Hybrid. I have a TitanX Hybrid and that thing is amazing. Never gets above 50C with a mild overclock.
At 1440p your CPU might be a slight bottleneck for a 980 ti, shouldn't be terrible but its something to be aware of as you may notice lower frame rates than what you see in benchmarks.