HiYoSilver,
It seems to me like you have a fair idea of what you need, with just a few ambiguities on a few points that any decent frame designer can help you with.
The most confusing part for me is I'm not sure how you create an aero touring bike. If you want to mount aero bars for a randonee style event, cool, but if you want a touring bike, they're usually not conducive to cheating the wind.
I think the best thing you can do is have a search of all the custom builders out there, and find one who you can relate to/empathise with, and have a chat to them.
Off the top of my head, I think Ti and Steel are your best bet, and once you have your functional requirments a bit more narrowed down and focussed, I think your custom concept will be a good one.