considering your ample budget... 3x8 MTB drivetrain, XT, or better... avoid sram, their stuff is finicky and just doesnt last as long... Durability is an issue with the Hollowtech II bottom brackets, so consider that factor... a high-end, sealed BB will be nearly as strong, and last much longer, IMO.... AVOID GXP BB's... they seem to fail like clockwork, i swear! unless you rarely ride your bike, of course.......

canti brakes are stronger, and will help when your bike is loaded up for touring. A bit tricky to get set-up properly, though, and more easily damaged in a hard crash... put on Kool Stop orange(salmon) pads, or the dual friction black/orange type, if you will be riding mostly in the warmer, drier, months.

Hubs... once again, the XT or better ones will have the qualities you seek... seals are a must for all weather use. the off-road stuff is meant to handle abuse and mud/water...

RIMS... STOUT, double-walled rims... don't even consider less, or you will be truing rims a LOT, if not actually REPLACING them... and get good quality stainless steel spokes.... DT are the standard, go-to, quality spokes.... then have a GOOD wheel builder build them... Sugar Wheels in Portland is my recommendation... those folks do a superb job! There may be a closer, GOOD, wheels shop near you.

CABLES... Jagwire's higher cable set is highly advised... they are lightly ground for an easy pull, and their top of the line sets are teflon coated, plus the housings/end caps are nice, too... this cable set will prevent early failure of the cables, and rust is not an issue.

Chains... get a shimano ultegra or XT/XTR grade chain... and get the correct one for an 8 speed setup.

FRAME... get a good one, with matching fork that has pannier inserts half way up the fork leg.... and MAKE CERTAIN it is the correct size for YOU. I prefer Chrome Moly frames... Comfort, strength, and DURABILITY is the reasoning there.

SEATS... the single most important thing on a touring bike... have an experienced fitter help you find the correct one... and if the shop won't let you TEST RIDE the seat, then walk out, and find a different shop.