Welp, it's here. Insert the "I have no idea what I'm doing" dog meme.
I dragged my feet on monitors for a few days, but I started digging into them last night, and...hoo boy. I guess between ignorance and naivete, I hadn't realized that LCD technology has stagnated in a bunch of ways over the past several years. That TN-vs-IPS divide is a *****: if you get great color and viewing angles, you have to sacrifice the ability to see anything better than 60FPS. (You can apparently get both, if you want to spend like $900, which is a biiiiit excessive as far as I'm concerned.) At this point it seems like you almost have to grit your teeth and bear with it until OLED technology matures enough to enter the market. I did find a really highly-rated 144Hz 1ms TN display from ASUS that I'll link in here, but I still don't know if it's worth giving up on IPS, since I'm obviously going to be using my machine for more than just pure gaming. But while I figure that out, what I should ponder is whether my ancient CRT can survive 1600x1200 without bursting into flames.
(I also saw someone mention this prospective display technology whose name I can't remember, where each pixel is essentially its own electron gun. Apparently it would have been pretty much the best of all worlds display-wise...but then all the manufacturers cut off their research as LCDs became ubiquitous. Figures.)
EDIT: It's running! And installing Windows 7! And it drew some blood, so it's a real build! And I'm...freaking exhausted.

You guys didn't mention how emotionally draining this would be. The build itself went really well as a whole. I can't say enough about this case's plethora of openings for cable management (just do me a favor and don't look behind the motherboard). I did run into one glitch the first time I fired everything up: when I was just booting into the BIOS, the stock CPU fan started screaming like a turboprop, and the CPU temp climbed to 70 and seemed to want to keep going. Turns out I hadn't properly fastened it into place, so it wasn't making full contact with the CPU. (Also didn't realize that even the pre-applied thermal paste winds up going all gooey when you start running.) Even without an aftermarket cooler, I figured I'd **** that part up somehow.

It took me a few tries, but I got it to click in properly, and now the thing sounds fine. Of course I might have avoided this if Intel's directions had included any text whatsoever instead of essentially being a goddamn LEGO manual...
Oh, and
here's the ASUS TN display I mentioned earlier. But while I was looking that up, lo and behold
this 144 Hz IPS pops up for a $200 discount, and it's 2560x1440 to boot. That's still about $200 more than I'd really wanted to spend as my max, but it seems like an absolute beast of a choice, and if it's going to last me a long time...hell, maybe I would splurge on it.
There's also
this AOC 27" job that gives 144 Hz. Damn this **** is complicated...