Size doesn't matter when it comes to performance, only resolution. More pixels = more processing. You can change the resolution and settings, but it is best to run LCD monitors at their native resolution for the best results. Greater size at the same resolution means the pixel density is lower, so the picture will be less sharp as you go up in size at a given resolution.
Typical rules of thumb for 16:9: 21-24" 1080p, 25-28" 1440p, 28-34" 4K to maintain density. 21:9 muddles things a bit, but basically the same applies. a 29" 2560x1080p is about as big as you want to go. 34" should be 3440x1440. Not really any way for 4K ultrawides to be properly run yet, so doesn't really matter.
IPS provides good color reproduction and good viewing angles, at the expense of some response time.
VA panels are a good mix of color reproduction and fast response times. They suffer a little when it comes to viewing angles.
TN panels are fast, but have poor color and bad viewing angles.
A lot of your high refresh rate panels are VA and TN, where performance matters more than appearance. There are many IPS/PLS displays out there that are plenty good for gaming. Anything with a 5ms response time or better is usually the recommendation.
So if you are a fast paced first person shooter gamer, and you want the best possible response times you go with a high refresh 1080p panel, usually 24" 144hz, 180hz, or 240hz depending on your budget.
If you play a lot of RPGs or MMOs then you might want the IPS display so you can experience the game's color closer to what it looked like when it was designed. Also a chance for higher resolutions if FPS isn't all that important to you. Same could be said for RTS games or even turn based games.
VA, is a nice mix, and many offer curved displays. Whether that helps with immersion is up to you. Greater screen size can help with immersion as well, but you have to balance that with how much you have to look around to see game menus and things. In game UI doesn't always scale with screen resolution.