I think the answer is, “it depends”.
Assuming an FDC+ for your disk controller, I would use the following:
1) Real 8” floppy drives: Mike’s buffered CP/M 2.2.
2) Real 5.25” floppy drives: Mike’s 1.5MB CP/M 2.2.
3) Serial Drives: Mike’s 8MB CP/M 2.2
I see no benefit to using CP/M 3 for what I do.
I don’t think there is any difference between using a Z80 or 8080, other than inherent Z80 performance improvements, since all the CP/M images for Altair I know of are written for the 8080. Some CP/M images will not work with a Z80 since the timing is dependent on a 2MHz 8080.
All of the Altair CP/M images I’m aware of require a 2SIO and Altair-compatible disk controller like the FDC+. If you’re wanting to use any other hardware, like boards from
s100computers.com or a JAIR, then none of these images will work as none of them support “standard” interfaces.
So, it depends on your hardware and what you’re wanting to accomplish as to which CP/M is best.
I have started a repository of disk images for various disk controllers, but all need a 2SIO. Since this is project that is currently under development, content is subject change without notice and the documentation has not been written yet.