What about splitting a second boat with another couple in same situation as yourself? Then it's half the cost, half the maintenance time, and you probably won't have an issue with only getting access half the time.

BTW, I didn't mean the Ensign as a recommendation, or even a monohull. Just relating how my choice serves my needs/desires. Also, your choice of boat(s) may change over time, depending on how easy is your access to water & launching facilities, available time for boating, and age/interests of your family/children.
I know when my kids were very young, we spent more time on our motorboat, because it had high gunwales - (kids couldn't fall out or off of it), had shade from the bimini, and didn't tilt while underway, like a monohull, and had a motor - i.e. certainty about the situation. Now that they're older, they like all 3, for different reasons -
the catamaran - they get to go out on the wire, and in their words "it's fast & it's cool".
monohull - because it is bigger, it's more like a "pirate ship", they can hide or play out in cuddy cabin, etc.
Motorboat - tubing & kneeboarding, and for use as transportation - i.e. to get to restaurant on other side of lake in a predictable time.
You can see I haven't mentioned anything about my family racing, right now it's only I who race.