This is the best suggestion yet. Let’s be realistic surfing the amount you currently do in the conditions you mentioned you will become an average surfer at best so you may as well have fun.How about this -- go find one of those Modern Retro boards. They're cheap (for a longboard) and come in 9'1". (Why the 1"?) It will give you the opportunity to try a cheaper longboard that isn't crazy heavy or crazy long, and you will see if that's what you're looking for. I'll bet it would work great for you. I tried one out once (I think it was 10'0") and have to grudgingly admit that it felt surprisingly good and not thaaaat much different from a lot of the longboards I've owned. Ignore the liters -- it is irrelevant for longboards and is just listed so as not to alienate the shortboarder-turned-longboarder market.
Before I get flamed for suggesting what is essentially a modern day pop-out, I would argue that it will act as a gateway drug for him, ultimately leading him to the finer strains of surfcraft that the rest of us on here are addicted to.