I would echo the TMM fleet is well maintained and great staff. Lone Star would likely meet your needs and the kids can have smaller cabins.
We also do dinners centered around grill. Some suggestions Beef Tenderloin (or filet steaks), frozen fish (Same or Costco), Burgers, chickens, spaghetti (prepared at home), pulled pork (vac packed and frozen with sauce applied before packaging which keeps it moist, Shrimp and grits, hotdogs... Check out 24 can Polar Bear cooler. You can get lots of frozen meat in 1 or take 2. (I usually put polar bear cooler into a duffle bag to lessen pilferage in airport--- never been a problem with me). We usually eat out at Anegada and 1-2 other locations.

However, taking 2 boats has many advantages as well (more space). If you go this route, try to pick "sister boats" so features will be similar and performance will also be similar. We have done this with lots of fun as well.