Hi Cherise!
There are actually four miniature golf course at Disney. Two of these courses are located adjacent to Blizzard Beach. The "winter" course features winter-themed obstacles as you make your way to the North Pole. The "summer" course features beach-themed obstacles, including sand castles.
There are two additional mini golf courses located behind the Swan and Dolphin resorts. One of the courses here is based on
Fantasia, the classic Disney film, and the other, more challenging course, "Fairway Course" is a miniature version of a classic golf course.
All the courses are fun so it may come down to what is more convenient for your husband and son. You can read more about miniature golfing
here.
As far as your question on sea raycers, the cost is per boat. So if your son decides to ride with your husband, they would pay for one one. However, he may have more fun operating his own boat.
If your husband and son would like to do both of these activities while the girls are enjoying the afternoon tea, it might be a good idea to try one of the courses at Fantasia Gardens (behind the Swan and Dolphin) and then head over to one of the marinas in the Boardwalk area to rent a Sea Raycer (or two!).
Have a fabulous vacation! Diane :)