What you want first is low LOW maintenance reliability. Derailleurs just don't cut it.
You have the cash, so no reason to not get a Rohloff14. ZERO chance of failure, every gear is perfectly spaced, even spokes, lube goes a year or the common length tour, should just add some oil half way, can put the shifter on the toptube, gets better with age. Can use a chain case too.
Get a long frame with LESS than 2" slope, especially if not using drops.
Get a dyno hub. Mine is a flawless SA XL-FDD with a PERFECT drum brake. It'll easily do a whole lap around the world.
Last edited by GamblerGORD53; 06-13-22 at 01:44 PM.