The idea for the aerobars comes exactly from some Tour Divide cockpit I've seen on the web. I bought an aerobar with adjustable single arms it should work fine.

A dirt drop is very tempting but they comes all with 23.8mm dia. so I'll have to change controls. What about the Soma Gatorskin? similar dirt drop but with 22.2mm to take my mtb controls (and according to a review, is better with mtb control instead of road).

All in all I always had bikes with flat/rise bar, so a moustache/simil moustache it's probably the right way without mess things up.