Just doing a quick search came up with one sailboat charter company for the upper peninsula, Based out of Bayfield Wisconsin, but on Lake Superior on the Western end. They are close to the beautiful Apostle Islands, which in my opinion, are some of the most beautiful places on the planet to cruise. If you plan on chartering I would do it later in the summer from them, as the Lake Superior water stays very cold well into early summer, and even then never really warms up much, the best weather is in August/September. Bring clothes for all ranges of temperatures. I am not familiar with this company, but they do seem to have the business to keep them going, if that tells you much.
For something a little further south, in Northern lower Michigan, in Traverse City, the Great Lakes Sailing Company is a very popular, and well run charter. The Grand Traverse Bay is big and beautiful, and has several harbors for visiting. If you wish to go further, there are quite a few very nice harbors up and down the Lake Michigan coast, as well as several islands, Beaver Island, and North and South Manitou Islands. The weather will be much warmer, than the first one I mentioned, with this charter co.
Both of these companies have boats that would fit your bill. I was surprised to see the Superior Charters having a big catamaran(44' I think). Great Lakes Sailing Co, has one 35' Gemini.
Hope this helps, others will have more input as well. Have fun in my Great Lakes State!!