Long shaft
I looked at a few Tempests before buying my Oday 23. Congratulations, the Tempest is a great boat. It is a relatively heavy boat, so I would go with at least a 6 hp engine; higher hp if you will be boating in an area with strong currents or dicey weather. Whatever you buy, make sure that it is a long shaft model. Since the engine well on a Tempest means you cannot raise the engine out of the water, you might also want to discuss with the dealer how your potential outboard does with sacrificial zincs and how it takes anti-foulant paint. Also, make sure that the throttle will operate in whatever position it needs to be in to fit in the well(some throttles work better than others when folded). As another option, I know at least one Tempest owner who used to remove the outboard after every sail and store it across the well with the hatch closed. I also saw an outboard bracket mounted on the transom of a Tempest. Not quite as pretty, but much more practical than the engine well. Good luck and enjoy the boat! They are really overbuilt and will stand up to a good blow better than most boats their size.