I have a Comfort Ultra II (5.113), a serial UCM type 10 (5.092) and a UCM/CBUS (unsure of version), I also have a UCM05 on 6.008
I'm guessing that to upgrade all of the above (minus the UCM05) that i'll need to use the UCM05 with the programming cable for them all as I cant do it over the bus until they are all on greater version of code?
Yes you must use the UCM with programming cable to upgrade the Comfort and UCM/CBus to the latest firmware which must be at least 6.000 and above.
Note that only modules which have firmware 5.100 and abive can be upgraded by the programming cable. Your Comfort 5.113 is fine, but you need to check the UCM/Cbus firmware
The flashable UCM/Cbus should like like this
The UCM 5.092 is the older type UCM01 and cannot be upgraded to support Firmware upgrading by bus or by direct connection to PC