That much weight would be to much for any boat but to be honest i would almost evebn say the hobie 20. they have heaps of power so it would work better but having more than 3 people makes the job much more difficult. I own a hobie 16 and its about 17years old and i have taken out 6 people out and all up they would weight 360kg. The boat wasn't looking the best but it was still moving!!! An 18 can hold a heap of weight but if your going to sail with only 2 people with kids the 16 is a much better boat to learn in so think about what the boat is going to be used for!!

Have fun and sail fast!!!

From Julian