First I have to say I'm envious of your situtation!
Secondly, a piece of advice you'll likely see a lot is charter first
. Spend time on as many types of yachts as you can. Different sizes, different types, different brands even. Then when it comes time to pick one for yourself you'll have a strong sense of what you want or don't want, what features and floorplans you find work better for you and your family, etc. Arm yourself with as much experience and information as you can, so when it comes time to pick your own dream yacht, you'll know exactly
what you want.