With your experience, workspace, and tools, the bar conversion is really not a bad job, it just takes a while.
When you sit on the Busa, let go of the bars, sit up, and hold your hands in space to roughly where the dirtbike bars would be, but the real thing then is knee bend.
Lowered pegs do help, but there is still a considerable bend in your knees.
I'm not trying to steer you away from the Busa, but many of us have been there and done that.
If you want to tour, or ride for extended periods of time, the knee bend can be a little much, even with lower pegs.
One option would be a B-king, as the seating position is great.
It has great power stock, but flash the ecu to an unrestricted Busa bin file, and it comes alive.
Add a windshield for touring and you have a super comfortable rocket that you can ride all day, and get off of it without feeling crippled. Of the many bikes that I have had, it's probably the only one that I would buy another of.
Good luck in your search, and stick around regardless what kind of bike that you buy, as this is a Hayabusa And any other motorcylce site, as many of us ride other bikes too.
Welcome to the org