Hello and welcome to the L.E.F.
Thanks 38ac! Long time lurker, finally trying to put some of the information gleaned here to work. Looking at the recent instrumentation threads with great interest as well.
My reasoning for the 195 is based on what I've been reading up on the models and options - not practical experience. What I'm finding suggests that the ones with counterbalance are easier to live with, and I believe that means at least a 195 or larger - but I'm certainly no authority. Maybe you know if this is the case, or have experience that counterbalance isn't that big of a deal?
As for IDI, just thinking that the option for fuel flexibility would be nice to have. Again, with no hands on experience maybe the DI models are just as good? From reading it sounds like the IDI models may have a specific alpha character in the model number, but that varies based on factory, date, etc. They may also have a plugged port for a glow plug in the head but DI will not. I probably wouldn't be able to tell if I saw one either. Maybe someone will chime in to help clarify?