New PC needed

Hi mates, my old PC is giving me problems and I think the time has come to go thinking about changing it.
What do you recommend for a Mesa 5i25 card, a second-hand Dell that I have seen so well that you speak or an Asrock-type embedded system motherboard that I have also seen here?

A few days back i got two Fujitsu PC's
A fujitsu esprimo p700 e90+ tower with 4 core i5
and
A fujitsu esprimo p710 e85+ SFF with 2 core i3
Both have very good latency, even with Preempt-RT kernel it is in the 20000 range.
At 80 and 70 euro a piece respectively, very nice indeed !

My question especially is about the graphics and reliability, I do not want to have the conflict problems I had with this PC. As for latency, I can afford more of these 20,000 I understand, since I would connect the Mesa cards that I had to buy and still own (5i25 + 7i76).

It was going to be intended for the milling machine only, running linuxcnc and little else.