Rubin,

You could take a 5.0 (or 5.2 might be a better choice) and make it a uni ... but they just don't come out of the box balanced really well for that. the 5.5 Uni is a great boat and there are several mothballed that would probably sell if you could scratch them up. Other than that, to meet your requirements, I think you should take a look at the Hobie 17. The wing seats could be real inviting to the kids and the wife on occasion. The 17 has some sail longevity issues and isn't terribly buoant to hold a bunch of people. But it will certainly sail well with a couple of smallish adults on board and there are a lot more of them around.