Tri-X in Diafine is a safe bet, especially if you're pushing the film. There's always Rodinal, or it's different clone derivatives, if you like grain. Since it's one shot, it would be easier to develop when traveling. The stuff will last forever, and it's actually designed for slower films, although I use it w/ HP-5 and Tri-X w/ great results.
I've been trying out Tri-X in TD-16 from Photographers' Formulary lately, and I must say I like what I see from the first roll. This is a powder (2 part) that is advertised as a D76 type developer that has a shelf life of 6 months after you mix up a stock solution. That will be a huge improvement over the 3 weeks I get from D76 before it gets strange. Perfectly useable after that, but it isn't like it was when it was fresh.