Unlike child support, spousal support is often very difficult (if not impossible) to modify after the divorce is final, so getting it right the first time is a must!
the other option if YOUR insurance plan does not cover them (although you said it will)... is the school insurance plan. Both my undergrad and graduate schools had GREAT affordable health plans. They were billed directly in with all my other school bills (tuition, etc). If you are willing to pay their insurance - you could have written into the decree that you will cover their insurance up to age X if they are in school. That if your insurance plan will not cover them, you will pay the cost of the insurance plan OFFERED through the school.
-------------------- Today you are You, that is truer than true. There is no one alive who is Youer than You.
Dr. Seuss