https://forumserver.twoplustwo.com/s...rchid=63135666
There have been a lot of solver build threads recently. Take a look through those to get some ideas of what's out there and what it will cost. CPU/memory requirements very tremendously based on what sort of problem sets your solving for and what an acceptable solve time is. It is much more effective to set a soft budget and see what performance you can get at that level and decide what is worth it for you.
Otherwise the answer to your question as posed is probably some screaming space heater of an end of life server with 128GB RAM, but that's not the life optimal solution.