one of those is 64mb to run really nicely, one is 256mb at the start and probably 2GB+ by the end, and the last one is like, you really probably want at least 16, 8 is getting to be a scant spec choice even today. Going for 2x32gb is less than $100 now! (good time to buy, flash and DRAM are glutted and this won't last forever)
NT was solid enough as a UI (although iirc NT 3.5 was sort of "3.11 and a half") but by NT 4 and win2000 it had pretty much emerged into the modern UX. And Win2000 still ran on peanuts by modern standards. I never used NT but my dad generally thought highly of it afaik.
I suppose there's an interesting parallel between macos trying to shed cooperative multitaking (and the legacy of the pre-32 bit ROM) with windows 6/7 and windows finally maturing in the 3.1-95 and NT-win2000 era with shedding the legacy of DOS and the low-level x86 poking. OSs seemed to hit a point in that era where it was no longer tolerable to support their legacy shit forever from the hobby-hardware era.