_My_ TL;DR two-bit opinions
1. Gsync/FreeSync is awesome for gaming, and "worth it."
2. TN panels suck so bad I can't even.
3. Fast refresh rates are excuses to sell TN panels and make more money (I know, I know, harsh...sorry)
4. IPS is good, I hear VA is great but no long term experience with it.
5. 2560x1440 is my sweet spot res right now. 4K just was not worth the tradeoffs for me but was cool for photo editing.
6. You will keep your monitor for a long time. I would put the money into getting something perfect for you.
Thought dump:
I've had the luxury of getting to use a bunch of different monitors. I know some gamers love high refresh rate monitors, and I get it. But the tradeoffs for a TN panel is just not worth it to me. If I was into competitive shooters then I would. Don't get me wrong, I love CSGO and Overwatch, but 60hz is fine for me and frame syncing is glorious. Gsync is incredible and I prefer it to Freesync, but it is more money and its not much better. Colors and eveness in lighting really supper matter to me. I don't know if you have a Frys or Microcenter or something where you could go look and see the monitor before dropping a bunch of cash on one.
Finally, if you do go with a TN display...not all TN displays are created equal. Same for IPS or anything else. I have a really high end TN display that is perfectly acceptable to me for gaming, but I hate it for photo work. Now I use it for testing systems. My current pro-art IPS monitor though is awesome for me and I love it.
GOOD LUCK