I am laughing (out loud, but not quite rolling on the floor) -I just
came across one wonderful and very cute craft that you might want to
check out on uk.rec.sailing, the post is 'Is this the ugliest dinghy?'
I suggest ignore all the jovial bantering, it's just fun, I think the
boat has a lot of merits -horses for causes. The more I think of it the
more I want one -reckon I'd be grinning non-stop playing about,
probably name her Puff the Magic Dragon now, or maybe Toy Boy, or Play
Thing. She is wider than your spec but you might figure out how to make
things work for car-top and compact trolley-wheels (like for kayaks).
Also you may be in a different country but then again...

Let us know what you end up with...

Solo Thesailor
http://sailingstoriesandtips.blogspot.com