Depending on how much you would like to spend

(1) https://www8.hp.com/us/en/workstations/desktops/index.html

(2) https://www.ebay.com/itm/HP-Z840-Workstation-12-Core-Xeon-E5-2680-v3-2-5GHz-32GB-512GB-SSD-1TB-K4200/373014396867?hash=item56d963ffc3:g:LQ0AAOSws6tejNUX

Personally I like HP workstations.