Fully programmable would a big plus. With PBT keycaps out of box, preferable.
Is there anything else, expect Leopold FC660M? Do i remember correctly that there were some editions of FC660M with dye sub keycaps included?
I could alternatively look for TKL board, but would like to see if there's anything fitting with a smaller form factor.
The only two that I know in the strictly 60% form factor are the Poker X and the KBT Pure (but
not the Pure Pro).
The Poker 2, the HHKB, the FC660C and many recent keyboards are unfortunately all USB only.
The Poker is not programmable, but for me it was interesting precisely because it is PS/2: I have several adapters made by Hasu that convert any PS/2 keyboard into a FULLY programmable one. However the adapter connects to the computer with a USB interface. So the Poker X plus the adapter is actually a USB keyboard, seen from the computer.
I know for sure that the FC660C is USB only. I don't know about the FC660M, but don't assume it is until you get the info from a trustable source.
The Cherry G84-4100 is PS/2. It has a small form factor. But you will need to lube the switches: they are Cherry ML and really need to be lubricated. Once they are, it's a decent keyboard.