I stepped up from a 24 to a 27 footer last year. I was looking at 30 foot Tiaras. They are great boats but unless you are looking to spend over 80k you are looking at an early 90s model with lots of hours. I just couldn't come to terms with buying something that expensive when you are lucky to use it 5 months a year. A couple of other things that made me reconsider going over 28:
1. Cost of maintenance for twin engines
2. If you have boat issues you have to pay for a mobile mechanic as most boats that size are difficult to trailer and good luck getting anyone to see you timely if you have issues in late spring/early summer as that's when everyone seems to have issues.
3. 30 footer may more comfortable for running in and out but trolling in anything 4 plus feet still isn't fun.
If you are looking for fun at dock but still room to fish I would go with something between 24 and 27. I saw some nice looking Bahas and Sportcrafts in the 2000s that should fit your bill for 25k to 40k. Just get survey, sea trial etc. prior to buying. I recommend looking in the southeast MI area and northwest OH area. Lots of more dual purpose boats over there. It seems like most of the boats that I found on the west side of MI were more pleasure than fishing.
Having a slipped boat is fun as you can meet some great people but if you get next to the wrong people it can be a long summer. Also, if you are planning to spend the night on the boat often, buy something with an air conditioner!
The South End provides useful resources and discussion forums for those that fish The South End of Lake Michigan for Salmon, Steelhead, Perch, and Bass as well as elsewhere in the Region and Chicago area.