Totally agree with the last two posters...Definitely the hone....
Plenty of shops that do on demand T&C grinding and there are business that will make specials of cutters if needed...work that IMO takes time and skill to get right.
I have both a Sunnen MBB 1660 and a #2 Cinci, and like Dan my hone sees almost constant service for fitting bushings and other parts that are difficult to do on the lathe or mill...not to mention the finishing of hardened parts.
Have a nice #2 Cinci...but since i got my Myford ID/OD cylindrical grinder the Cinci sees little work!
Big thing about a hone is you gotta tool it up....stones and mandrels, shoes and the like...Buying the machine is the easy and cheap part.
Further, fro prototype and one-off's you don't need a power stoker....Wasted expense in my book....the hand stroke machine will do just fine.
Sunnen used to have two sales divisions...Automotive and industrial....The industrial machines (green) are better with adjustable mandrel centering and more speeds. Currently think they now
just make one style machine...more to the industrial design.
Assume you are going to have a surface grinder.
Cheers Ross