The G-Cat 5.0 (~16') fits exactly what you are looking for. It sails well, but has no boards to deal with. It is built tough, has three crossbeams and two trampolines so it has the space for all 4 people (plus, it has the buoyancy to HOLD all 4 people), and it is small enough for one big guy to right solo. It is very simply rigged. It is at least as fast as a Hobie 16.

There is one for sale near me in Palmetto, check the Sarasota-Bradenton craigslist.
<-- clicky

I'm currently restoring a 5.7 (~18'), and wishing I had a 5.0. I solo a lot and I can't right the 5.7 by myself so I must be very careful. I'm thinking about making a telescoping righting pole to assist solo-righting...