If you are going PC then just build your own. Waste of money to get a preassembled system, and it is a joy to put your own thing together.
I am slowly assembling parts for a mini itx build. I have a nxzt manta mini itx case, and a Asus mini itx motherboard in a box awaiting brains.
I have been debating what to get. I just ordered the monitor I will be using for my Mac mini, and PC so I will shoot for rock solid 1440p.
A gtx 1070 should suffice. Total cost will be around $1000, and it should run with Mac pros, let alone Mac minis.