: Starting out in the sport with a surf ski? Well he'll either learn quickly
: or get quickly disgusted with the sport and quit, more likely the later.

That's certainly a possibility, though "more likely" isn't necessarily the case. The young man is touted as a very athletic (cyclist,runner) thrill-seeker (motorcycle racer). I'd actually recommend whitewater river kayaking to him, over the "thrills" of lake paddling!
A surf-ski, while obviously disconcerting at first, seems - to me - to be ideal for what the OP was describing. Just like learning to ride a bike, or learning to ski or snowboard, there's a quick and rewarding learning curve. And, once the basics are mastered, he'll still have a boat that his skills can continue to grow with - and a boat that will always provide him with plenty of fun, in any number of conditions.
And on inland lakes and rivers, seeking out wind and waves, it doesn't sound like he's looking at major expeditions, just fun on the water. So, what need has he for storage, and all the paraphernalia of a traditional kayak? A ski is simplicity itself - no skirts or pumps, or re-entry devices, etc. Just put it in the water, get on, and start paddling.

Anyway, that's my take on why a ski is what I'd recommend for what the OP described. Maybe the young man would quickly grow discouraged, maybe not. But then again - thrill seeking athlete that he is - maybe he'd quickly grow discouraged with a (relatively) stodgy traditional boat, too?

Dave

BTW, Prijon has my recommendation for a "good plastic boat" - they make fine, and very strong, whitewater river kayaks . . . .