if you’re just coloring for web, sRGB 8bpc gamut is all you need the monitor to support. I wouldn’t blow money on a P3 10 bit monitor, just say’in. just buy a spyder for calibration.
the 4k option will be a big jump in price, so plan accordingly if you have to go that route. it is possible to grade 4k on a non-4k monitor.
if you do have money for it, a blackmagic decklink 4k card, 10 bit Rec 2020 broadcast quality monitor, 10 bit nVidia card etc. but I’m assuming you’re looking for bargain options.