Trust company
You might consider looking at a company that provide trust agreements. I have my N-reg aircraft registered to Southern Aircraft Consultancy, with myself as the beneficial owner. The agreement covers control of the aircraft, death of the person etc: I had solicitors look at it and they were satisfied.
SAC have a few hundred N-reg aircraft registered to them. SAC are based in the UK, but run by an American citizen. Cost is much lower than the figures you have given (PM me and I will give you the details).
There may be other like companies but my experience with SAC has been very positive. (Plus got a discount off my insurance as a result.)