SUP for kids design question

Anyone have any recommendations for designing a SUP for kids to use. I have 3 kids and they range from 13yrs(75#@60") to 17yrs(150#@72") and want to know what factors are used in design, keeping in mind they have limited surf experiance and are growing like crazy. I have downloaded the AKU shaper program and want all the input I can get. Tried searching before asking but did not find much on the subject. I am in flatsville Gulfcoast Florida, so small to non-existant waves are the norm.

Thanks

your 17yr old is pretty much mansized, and like you said they are growing, so a normal, SUP should be fine.