Re: S2 7.9
The 7.9 is a great sailing boat. I have raced on them numerous times. They, like all the older "performance" boats, have maintenance issues. There is a very active club that races them, you can google the site.
They would prefer that you race but are very friendly and will answer your questions.
The boat handles the normal weather on the Great Lakes quite well. Raising the dagger board, which weighs about 600 pounds, is an effort but you would only do this when you are ready to haul. Teh starboard cabin top winch that you use for this is the biggest winch on the boat.
The boats over #400 are sought after by avid racers so you will not get a deal on one of those. The BMW engine has not aged well. An outboard with an alternator is a good cruising option.
As allways a really good survey is required.