Hans Geissler was actually a salesman for Sizzler before their demise, and took some of what he learned from their design and incorporated it into the G-Cat.

Speaking of G-Cats, it would be easy to widen a 5.7M and turn it into a psuedo 18sq ('cept it's 9" too long). The mast, mast-beam and aft-beam are H16 mast sections and the fore-beam is a H14 mast section. You could cut the G-Cat mast and turn it into the rear two beams, cut a H14 mast and turn it into a front beam, and then slap a taller mast on it and run a big mainsail.

I've given a lot of serious consideration to widening my boat to 10-12'... but keeping the same rig + a screacher. This should turn it into a nice all-weather Gulf of Mexico boat