I thought the rear end look familier. A good choice, as there are a range of ratios available which are a simple bolt in exchange. and a cheap LSD diff from a WRX can be used . You rear end set up is nice, but wounder about "body" roll when cornering. I have plans that use the subaru rear end. there is a 50mm limit to the travel to allow for absorbsion of road bumps, but on corners it limits the "roll" . JP trikes has a formula for working out the front king pin inclination, which is very important for the steering geometry. The remote link steering I have seen has always incorporated two bars between the trees, for that situation where failure of one joint is not a possible incident creator. plus there is the possibility of having multiple points on the trees that can alter the effort for turning the trike.small movement for highway riding, long for city, adjustable to suit the rider and conditions. I am interested is what transmission you are using, and that, using a honda bike motor, will it need to be registered as a bike or a car?