Hi Ludu,
I ordered my last system from iBuildMacs (https://ibuildmacs.com). Jon Soliemon was very supportive to find the right configuration for use with HW. I finally ordered a Mac 6,1 (cylinder), which is almost noiseless.
If you prefer a Windows machine, Jon also offers used HP Workstations (https://zworkstations.com). These systems have no limit: up to 40 cores and 2 TB of RAM !!! This should be enough for the next couple of years
It is possible to run a system with only SSD, but there is no need to store your sample sets on an SSD. If you store the sample sets on a HD and keep the cache on an SSD, your system is only marginally slower.
Best, Chris