Well I would recommend...
I'm 23k miles into a RTW trip, and had great experiences with Heidenau K60 tyres.
They lasted something stupid like 12,000 miles, maybe more I can't remember.
MEFO Super explorers may be equal or better, but pain to find in the UK.
I would highly recommend spraying some WD40 or similar into the spoke nipples, and giving them a 1/4 turn one way, then back again.
Just to make sure they don't seize in there.
Mine did, and I'm scrapping the wheel.
Have fun, it's a great bike eh