Catamarans would be more stable, seawise, if designed correctly, but beefing up the bridgedeck crosspieces would be hell if this is the design they want--and in any case, it's still too top-heavy and far too heavy. (We're building a catamaran. I know about this stuff, via by hubby.) One good wave & I'd expect to see it crack right down the middle like an egg.
Structurally, it'd be impossible with this design. It'd have to be whole lot lower and a whole lot wider (most cats are a 2:1 ratio, length to width). That'd also make it less manueverable--watching it try to turn might just be as much fun as watching people take out their bass boats at our old marina (I wanted the tire concession). In fact, they might as well buy an island declare themselves the Emporers of Ice Cream.
This idea--and this boat (even designed as a catamaran) ain't going nowhere.