Winter boat sales are typically slow. You may be able to negotiate a better deal now. As far as the type and size, a few days with a captain and you will get yourself around enough to make things work. The splitting the rent with other sailors is the safest option - but will that get you what you want? If so... it sounds like a win-win.
As far as the Catalina, it is the right choice and a good solid boat with great resale (as far as boats go). Let me know models that you like and I will give you an honest evaluation.
PS Good to hear on the kids. If sailing is your passion, your kids will become passionate about it too. It is an adventure the family will love.