So many choices
Art,
Hard to define what is "best". You'll probably get a lot of answers with all of our personal preferences, kind of like the taildragger or tricycle debate. You may want to get in touch with Mahlon at Mattituck, or Bob at Eagle engines. Mahlon is frequently on the forums with great information.
I'm not the best one to answer you, since I haven't even started my engine yet, but I can share how I made my decision. I had Eagle Engines make my powerplant for me last year with Superior parts. It is a 180hp, vertically inducted IO360. I wanted to stay away from the angle valve engine because it is quite a bit heavier than the parallel valve version, and everyone says that 8's tend to be nose heavy anyway. I was going to go with a carb, but made my engine purchase right about the time that MSA stopped making them. Since their future was uncertain I went injected. I decided to go with a vertically inducted system because the horizontally inducted engine added about $2K to the price. The only downside now is that since Superior went out of business, I don't expect any warranty service other than what Eagle Engines provides me. The folks at Eagle and American Propeller were great to work with.
