My 2 cents. Yes I have one, but no its not for sale - sorry. Its for my daughter to sail maybe once or twice a year

I taught my son when he was 7, so it is possible it just takes sacrifice. The trouble with most of the dad's is they want to sail as well, and you just can't. It takes about 2 years of hard work but totally worth it. My son is now 12, and sails rings around most people. So my point here is - spend the money and get a board with a centreboard. The starboard go, the new bigger atomics are good. The wind-sups are ok, but to be honest will not stay upwind well enough which is a real drag for both you and the kids. The board you get, will not really lose that much in re-sale, as everybody needs / wants a learner board, so just look after it and you'll get your coin back.
More importantly, do you have small enough sails? I used a 0.8 and 1.2 to start my son on. Happy to help when the wind comes back. Otherwise head in and chat with Simon at BC. He knows my boy well, and was invaluable in both with teaching and setting up the right gear.
Best of Luck.
This is him as a 9yo.

Last season.