Theres already hundreads of threads on this subject if you use the search button
Anyway....
The only surf school I have experienced first hand is the one actully on Fistral beach. The instructors were really cool and I had a great day
Others to checkout would be
www.121surfcoach.com
http://www.extremeacademy.co.uk
Roescliston is a great campsite but depending on the weather in sept you might be beter off a B&B i'm sure someone else can advise you on that
dude