Need surf board for the kids, please recommend

Just got my boat and the kids are going to want to surf next year, so what surf board should I look at? 40-80lbs kids. Beginner level but will move to intermediate quickly.
Since they are lightweight, should I go shorter with a skim board?

My wife and I are skinny too at 115 and 150lbs. I think we are going to share an Inland Surfer Blue to start with. Hopefully they'll be running some specials soon. Any other recommendations?

Thanks

We purchased a surfboard on a whim with no research. It is a 5ft O'Brien Alias. My 12 year old daughter (who is small for her age) learned to ride it this year and can ride forever. I can ride for a short time, but true surfers tell me I need a bigger board. I am 180 lbs. A 5ft board may be perfect for you family. Hope this helps.