My first thought:
So in reference to your desire for a gaming card that'll last five years, I think it would be a good idea for you to view the high end gaming GPUs back in 2013:
The AMD Radeon R9 290X, and the GeForce GTX 780 Ti. According to my Google queries, they had launch prices of $549 and $699 respectively. I recommend that you load YouTube, and search the name of a game(s) that you're interested in with the name of one of the cards. e.g. assassins creed origins 780 Ti
YouTube query result:
DudeRandom84: Assassin's Creed Origins GTX 1080 TI Vs GTX 980 TI Vs GTX 780 TI Frame Rate Comparison
*1440p game play
https://www.youtube.com/watch?v=nyThJMSDayc
You can do the same searchs with games like GTA 5 and Witcher 3, but just keep in mind that those games came out in 2013 and 2015 respectively, therefore it would make sense that they'd perform well with 2018 technology.
My second thought:
The new Nvidia graphics cards are due out for release very soon; perhaps this July or August. So I'd wait on purchasing a high end, and expensive, GPU until than. With that said, two months can be an eternity for a gamer, especially when the big summer steam sale is 2 1/2 weeks away: https://www.whenisthenextsteamsale.com/
In your position, I would inquire with PC gamer friends to see if any of them had a spare GPU that they could lend me for the next two months. If that wasn't an option, I would venture to purchase a low-mid tier GPU to hold me over for the next 1-2 months. How low end? I probably wouldn't buy above a 1050 Ti, and with those cards now costing $200 ($50 over original MSRP), I'd be open to an EVGA b-stock (factory recertified) unit, but only if the prices were $150 or less (https://www.evga.com/products/product.aspx?pn=04G-P4-6255-RX). Then after the new Nvidia cards come out, I'd sell the low end card. This is what I would do...
If you don't want to bother with the procedure above, and you simply want to buy the best GPU available today, then I personally think that this is it:
https://www.evga.com/products/product.aspx?pn=11G-P4-6698-KR
If you go to the website images.google.com and query the name of the GPU and your case, you'll see how you'd mount this graphics card with the included and permanently attached water cooler/radiator:
https://www.google.com/search?tbm=isch&source=hp&biw=1920&bih=1063&ei=ReQSW7HGGceN5wK5o6aIAg&q=GTX+1080+Ti+FTW3+HYBRID+define+r5&oq=GTX+1080+Ti+FTW3+HYBRID+define+r5&gs_l=img.3...9363.15182.0.15591.16.3.2.11.12.0.76.76.1.1.0....0...1ac.1j2.64.img..2.3.86.0..0i24k1.0.vlqV_aibOY0
One last thing... Once you've settled into your high end graphics card, you should keep an open mind about raising your game play (and upgrading your monitor) above 1080p 60 Hz. 1440p @ 144 (or 165) Hz is a huge upgrade. It may not sound like it on paper, but believe me, it is. My other favorite resolution is 3440 x 1440 @100Hz (ultrawide 1440p). I'd even consider 60 Hz in the 3440x1440 resolution, if the price was very competitive (<$600 USD). Just something to think about.