Your compressors mentioned will be working at refrigeration duty rather than AC duty and as such will be derated from the original design BTU/hr. The range the evaporator coil ends up running in can be used to roughly determine what kind of real capacity to expect from MFG. data. I would ask the compresor OEM what the compressors will do at 20F evaporator which is typical design figure. We have an older type built up system that uses a plate type heat exchanger made by Alfa Laval which ports to a good sized well. The way the condensing units are sized for this setup has proven to be tricky.
I would be interested in hearing how the coils were sized, the control arrangement, and how the system performs.