SOS, need graphics card help ASAP

I am building a new PC and something happened, and the people I am ordering parts from were nice enough to allow me to pick a different graphics card rather than wait a month in back order. My problem is this; should I get a gtx 960 4gb, r9 290 4gb, or gtx 970 3.5gb :( ? I got a bit more money and can upgrade from what I picked before and might be able to fit the 970.
I'll be doing mostly 1440p light to intense gaming and sporadic 3d design in some graphics card-utilizing programs. I'd like some suggestions on what would be the best option for me. The internet is less than definitive in its information and reviews.

So 960 4gb, r9 290, 970? Or should I wait until maybe the 16th (idk) for the r9 300 series?

Thanks.

I cannot get something more than the price of a 970, and I am in Canada so unless you know good deals in Canada I can't go for U.S. deals (curse you border limits and duty!)

the r9 290 will be the best performer from what you listed

The gtx970 would be fine if you dont want amd

Thanks, may I ask why the r9 290 would be best? I'd like to know what it's benefits specifically are before I purchase. Sry I'm OCD about this kind of stuff.

it has a 512 bit bus as well as more rops than the nvidia cards... in other words, it's built for resolutions higher than 1080p where as Nvidia cards are gimped at higher res.

Neat, I never would have expected that, you would think NVIDIA would have cards built for higher res, maybe it's just their higher ends cards.
One more question though. Is there a big enough difference between the 290 and 290x to justify the price difference. I found a 290x for gtx 970 price.
Thanks again.

OK thanks guys I'm going to either get the 970 or r9 290(x) based on what the store has, r9 290 probably. I will wait a few days though, r9 300 series news and leaks are on fire I might as well see if they are coming out this month or later.
bye.