Just twisted through the thread, sweet build but a Taxa product is not for me. Not strong enough. The composite paneling maybe light and well engineered but it cannot take a hit. So yeah I never got a reply from Trailermadetrailer as I looked locally first at quite a few trailer manufacturers. It did not appear that they worked in aluminum frames...Came to realize most of the ‘custom’ trailer operation buy shells/frame from big trailer manufacturers and then modify them for customers since presumably the big guys are USDOT/NHTSA registered making interstate sale easier. Alum-line said they could build it so I will get a price from them, and another from a new off-road camper upstart in Nevada.
You might have to do it all yourself, sounds like you know exactly what you want and how you want it built. Those criteria make it unlikely you will find a craftsman willing to commit to the project. The easy way to get something built is to have a general idea and compromise, modify the plan to just "git 'er done".
OR have a full set of comprehensive plans, a full spec, and put that out to tender. You have neither and are super critical of every suggestion. You need to do it all in house, one stage at a time, with an unlimited budget.
At the very least you need to state where you live. This is an international forum, hate to see you fall in love with a guy 25,000 miles away.