So here's my decision. I really like the water cooled sandstone wheel idea. I could get a second hand traditional sandstone wheel on eBay and attach a motor. But that will take a little bit of time to organise so in the meantime I'm looking into getting a CBN wheel. I have a few reservations about this...
1. all the reviews I can find about CBN gringing wheel seem to be from turners who use HSS tools, I'm a cabinetmaker and most of my tools are 01 or A2 steel so not sure if I'll have problems overheating tools or clogging up the wheels with the softer 01/A2 steels.
2. I've used diamond bench stones for honing in the past (admittedly not the most expensive available) and found that they become duller more quickly than the manufacturers had suggested. CBN is claimed to last a lifetime but from what I have read it is slightly softer than diamond so not sure if I trust tge claims made about it's longevity.
Any advise on these topics would be greatly appreciated.