I've heard good things about the Dell U2715H which is 2560 x 1440. You can run 2 of these and I would have gone with that if I hadn't already got an LG 27UD68P 4K which I run at 2560 x 1440 (not HiDPI grrrrrr)
The Mac Mini is ancient. 4th Gen Intel Processor. We're on 8th Gen here in 2018.
I'd suggest an Intel NUC w/ Linux Mint or Windows 10 if you want a mini desktop.
Otherwise I'd get a MBP or iMac if you really want MacOS.