Wow. I've been thinking of doing something similar to the OP and read this entire thread with interest. What a waste of time, as most were just critical off-topic replies which wouldn't be much help to the OP. Wherever you are, OP, I hope you are enjoying your boat.
I've wondered about the feasibility of purchasing a 32'-38' sailing catamaran and removing the mast and sails to sell (hopefully offset the purchase cost somewhat). Even used power cats are always so expensive but more older sailing cats to be found more reasonably priced. I realize that power cats have different hulls but the sailing cat sans sails should still be pretty darn efficient and loads of room for a liveaboard. If one could repower up a bit to have a frankenstein trawler cat that would be efficient at low speed (trawler-like gph) but have some 'umph' when you needed/wished to go faster, too. A poor man's power catamaran, so to speak. I wish I knew where to find info on doing something like that. Anyone know of a blog of resource of anyone that has done that or documented attempting?
The OP is gone, I think, so feel free to bash me now instead.