I've been waiting for the new UQ ROG for a year now since they announced it. Still not out. It combines all the best attributes of being IPS, 144hz capable, Gsync, but also 4k. Not going to be cheap, I'm guessing at least $1400 CDN.
I have 3 other ROG monitors, and have had 4 at one time, and a couple of the Acer gaming monitors like I said. Mitsu gave a good description of the +/- of various types. IPS IMO is the best all round way to go, it may not be the very best for photo editing, but it's far better than a TN/VA panel for that, and for gaming, while not quite as fast in terms of MS response, unless you are in the very top 1% of CS/FPS players and are a real $ making Pro, you'll never notice the difference. That's from someone who played CS in the CPL long long ago, and I have both the ROG TN panel and the IPS in 27".
If you move up a bit in $, get the 34" ROG or Acer 34" 100hz IPS panel, I have the ROG, but have seen the Acer frequently, and they are in fact the screen in the unit anyway. You can find them for 1600$ on sale frequently, or even less for the Acer, I've seen it for 1300$ on sale often. So if you're going for a single unit, get one of those, as they are IPS and great for both gaming and photo editing. If you're going to be a die hard photo/work user, then proceed that way, but honestly that monitor will not be great for gaming, not compared to even a regular 1080p 144hz you can buy for $300 for a 24" Asus, let alone a 27" 144 or 165hz IPS model. Also, the 35" ROG monitor is 200hz yes, but not IPS, while the 34" IPS version is 100hz. I tried both on the shop before getting the 34", it's far superior IMO, the eye can quickly tell 60hz from 100hz, but anything over 100hz isn't as noticeable a difference, if that makes sense. IE 144 to 165 is impossible to tell with the Pepsi challenge, and while 100 to 200 you can tell a bit, it's nothing compared to the 60 to 100 jump. IPS on the larger sized screen makes a huge difference in vibrancy, color, everything.
The future 4k 144hz 27" are really going to need serious power. I'm running 6850 Broadwell E CPUs with 1080 SLI, a 1080ti box and a Titan Pascal. Running 1440p at max, or 4k on my 28" right now, with a lot of graphics intensive games, is pushing it already. Volta will hopefully allow 4k at over 100fps in most stuff, I hope. I use VR for so many of the games I play right now, DCS and other flight sims, everything but ARMA3 and a couple FPS, that GPU power is critical to maintain that 90fps.