A Boeing 2707 would be lovely. Even a Lockheed L2000 also. They would take a lot of work to develop the accuracy needed because the real plane didn’t fly.
A lot of guesswork.
I would love Concorde as well but it needs to be study level with working INS, proper AFCS and other systems. I’ve used the FSLabs version before so anything less would be a step back.
Although I had the FSL version I stopped using FSX and also don’t have any FSL products installed since the controversy around them. I was a paying customer but that episode put me off them permanently.