I wonder if those angled flat sections on either side of the top deck might be a target for water to come on you from the side and spin you over. I also think that, once over, it might be hard to roll back up. I have an old kayak like that, it is most stable when upside down.
Twelve feet is a bit short unless you're going to stay off the ocean.
Of course, you'd go see it and try it out to make sure you fit. If you were pretty experienced, you might not be asking. But if you're *not* very experienced, I would go for a good buy on a polyethylene kayak from a known manufacturer. For example, I picked up a "demo" Necky Looksha Sport, 14.5', for $550 at a dealer's Olympic benefit auction.
Full Size Sail Rig
1 Canoe/Kayak Trailer