Tough (and fun) Choices....
Henry,
Before everyone jumps in with their favorite choices, I'll give a few general thoughts that I have come up with after reading many threads of this sort:
1) Most folks only buy one or two engnes in their homebuilding career (OK, some really addicted folks might buy a couple of more!), and therefore, have limited first-hand experience. Interestingly enough, most of it is GOOD! Not really surprising, because the good shops stay in business.
2) ANY of the good shops stay in business because they build reliable engines. If you want a good indication of how good their stuff is, ask how many engines they have built. They also stay in business becasue of their customer service, and responsiveness to problems. Listen for these stories.
3) Be careful with negative stories about shops. Most of them are here-say ("I had a friend who new a guy who was told by his uncle that..."). Most of the engine horror stories that I have heard over the years have been due to shade-tree overhauls, or really "iffy" attempts to get too much out of an engine's basic design.
4) After much research, you will find that the top shops all build tremendous engines, and all are heartily recomended by their customers - and rightly so! You will then discover that you are no closer to a choice (based on quality of engine) than you were when you started! Do not be surprised if such things as geography, shipping costs, and sales tax have more to do with your final decision than anything else.
Me? I went with a Mattituck TMX for a number of reasons, and have ben extremely happy with the engine (and the service that brought it to me) so far. You are starting an interesting journey - enjoy it!
Paul