Depending upon what size and type of boat you want you should in my opinion look for an engine package that is not the highest output one of that type and also consider the areas you will operate as far as shore side support goes. I am biased towards Caterpillar although they have made a few that I would not want to have on my own boat.
I tend to be biased to CAT as well, however other engine manufacturers have certain HP models that are real good engines as well. CAT's will be noisier, have a little more vibration and noise over some of their competitors, but most durable and parts/tech are easiest to come by. Also, sometimes one manufacturer is a better fit for a certain boat than the other one offered due to engine room layout, weight, power curve.
My quote from Sep 12 is still valid. You, I and many others have found our circle of ole Detroit techs. For the NFG to the Detroit world, he still may have to find and/or learn of (sometimes the hard way) their best tech and protection for their investment. There are to many wanna be mechanics out there who think they can fix anything, as long as all of their hours are on a clock. It's an old beast. The two strokes take an old ear and touch that has to be learned & earned in these modern days. Yes, Anybody can service them. The few can fix it quickly, the first time, get the respect and second call (bless them).
You've described the hazards of finding a reputable tech/shop for any engine, not just 92's. When MTU came out with the commonrail M-93 technicians needed to attend a continuing education special class in order to basically do anything on that model. I knew of quite a few captains who could not find people to work on them.