Very nice project!
Sorry I didn't comment while you were in the planning stage, but let me offer a comparison with the Island Packet Cat 35' that I owned for several years. That boat had a beam of 15', a center hull for breaking waves under the bridge and also for lowering the cabin sole to also lower the cabin roof so you could easily see over it from the center helm position near the transom (it was a sailboat after all).
You shouldn't have that problem with your pilot house helm position and your cabin height is much taller than mine.
Your weight target seems entirely achievable, maybe a bit conservative. My boat weighed about 18,000 lb light ship (measured on a travellift). Yours is longer but narrower and doesn't have the center hull or mast so you should easily hit the weight of 22,000 lbs.
My boat was really a full displacement hull, even though the hulls were narrow so the 1.34*sqrt(lwl) rule doesn't really hold it butwas very inefficient. It took full power from its twin 27 hp Yanmars to hit that value. It should be able to almost do that on one engine if it were an efficient full displacement hull.
Two things caused that I believe: the drag of the center hull and the relatively heavy weight for its length. So keep the weight down as best you can.
Post some interior renderings when you have them.
David