Quite an adventure you have planned. I haven't done a tour like that but I'd seriously consider the hydraulic discs. Route surely includes many steep hills where hydros shine. I have TRP Spyre & Avid BB7 cable discs which are pretty nice but on steep descents require a lot of lever effort. If the hydros get a problem I figure worst case is a few days to get new parts shipped in. & I'd go for the XT's or similar upgrade, IME brakes are the one component where it really pays to get the best quality.