No family but I’m the one who likes to do both. Kind of depends on which one of the items takes priority, skiing, tubing, or fishing. The other big one is the budget.
Disclaimer: hate tubing, love fishing and waterskiing
If tubing: It doesn’t matter a whole lot what you buy. As long as the family is comfortable in the boat and it’s easy in/out with a ladder. Can save on horsepower and get something that fishes well.
Skiing vs fishing. Most of the boats that are called a fish and ski are a very poor compromise. The one that starts as a fishing boat isn’t a great ski boat. The runabouts that pretend to be fishing boats are even worse.
Budget no issue the only one I’ve really liked is the Ranger Reata. They really thought that one through for both recreational and fishing uses.
Budget an issue: An aluminum fishing boat that has a good sized motor and has a mount point for a rope. If no mount point you can use a harness that attaches to the eyes on the stern. In addition to the Crestliner referenced above check out the Smokercraft Ultima.
Notes on motor: Dad has been a lifelong waterskier. His pet peeve(one of many) is an underpowered motor. You can never have too much horsepower. This can be self defeating on gas mileage but necessary to get adults out of the water properly. In the last thirty years he’s never had less than 170hp but none of the boats were worth a crap for fishing.