Well, running 45-50 VMs on a workstation is a wrong approach, anyway. There should be a linux server installed running ESXi. Ok, preferably on a separate room (it's going to need a lowered temperature room anyway).
I use MACs because of the availability, my knowledge and it turns out to be silent processing.
The heat dissipation has not been an issue, so far.
And, so far, I can scale up easily.