There is no 'Holosun SCS cut.'
The Holosun SCS is a family of 7 different sights with 7 different footprint, 5 of which are for proprietary optics cuts (Walther PDP, H&K VP9, M&P CORE 2.0, Glock MOS, and CZ P-10). The big selling point for most people on the SCS is that it allows for lower, direct mounting on pistols with factory optics cuts.
With that out of the way, if you already have an SCS MP2, you would want your slide cut to the M&P Core 2.0 pattern. C&H Precision does modify 1.0 CORE cuts to 2.0 CORE spec, so they or another shop that does the same might be able to do a 2.0 cut for you.
If you don't already have the SCS MP2, but are really sold on the idea of solar charging, I would recommend picking up the SCS 320. In spite of 320 being in the name, it's made for the Deltapoint Pro footprint, so you could have your slide milled for that non-proprietary footprint. If you want smaller, the SCS Carry uses the Holosun K footprint (modified Shield RMSc)
If you don't really care that much about solar charging, I would get a slide cut for the RMR pattern and use a 407C/507C/508T, or the Holosun K footprint and have my choice of SCS Carry, EPS, 407K/507K, etc.
