If you don't mind taking two vans, lots of companies have them. We've used these vehicles with Tiffany Towncar and Happy Limo for recent trips. Both the vehicles and the companies were fine. The vans hold from 10 to 14 people, depending on the size.
If you prefer to have everyone in the same vehicle, Happy Limo has a 32 passenger mini-bus that will take your group from MCO or from Disney hotels to the port. We used the min-bus a few trips ago. Lots of room and quite comfortable. I think a round trip from a Disney hotel to the port and back is in the $600.00 range. Divided up amongst a group that size, the cost per person is not too bad.
My guess is the cost would be about the same for either option (one vehicle or two).
Good luck.