Current / to-be-retired setup is a dedicated server using single 3rd gen i7 CPU and 16 GB RAM, so not much compared to today's standards anymore but has worked well and was a very reliable choice in the end.
New system will have two dedicated servers, both have single 8th gen i7 CPU, 64 GB RAM and NVMe storage disks. (Preliminary tests show that some background processes have about ten times faster speed...)
(Intel Xeon based setups might offer more speed but they become then quite costly, so the i7 is a good balance)