I think that one of the most difficult things will be to keep the cost less than 100K. My Tom Cat will be well over $120,000 with electronics. Cats are going to ride high on trailers, unless you "fold" A single fuel is not a problem--Wallas stove works on diesel (better on Kerosene) but I don't think that single fuel is a major issue--we found that a single bottle of propane lasted us about 3 to 6 months full time. The sailing part, with a cat rig, will be very difficult, because the boat has to be built for a mast--not just put on. Don't consider sailing to save money. There are times you can sail some distances, but the wind will not always be in your favor. We have done a lot of trolling under sail, and it works well. I have a friend who made a very minimal boat--which has sail (a Prindle 16 rig, and a 14 hp outboard which will do about 12 knots under power and an easy 8 knots under sail--but it is very light and made of composite materials, The cost was over 25K without labor, which was very intensive. The accomidations are minimal--and it is a wave piercing hull--I don't think it would be a good fishing boat--since the hulls go some distance aft from the cockpit. Another possibilty woud be one of the production cats, with small engines. Although the Tom Cat would fit your needs, it is not highly effecient at slow speeds (because the tunnel is not open at slow speeds--that is the water line is above the top of the tunnel, which creats a lot of drag at low speeds. Also since it is a planing boat, it is not very effecient at semi dispalcement speeds over 7 knots, until you get up to 22 mph. You might also consider one of the traction kites. This gets away from the mast--or at least a tall mast. Do some searching on the various forums and look at a number of boats. Bob Austin