757/767 would be a great fleet
I would say its an excellent choice. You won't work as hard as the short-bus drivers and you will get some diversity. You'll get to see everything from Dar Es Salaam to Moscow to Nassau to Philadelphia to Nice to Tel Aviv to Glasgow. Nice variety! I think those 777 drivers work pretty hard too with the constant over-the-pond flights for the junior pilots.
It's been said before on these boards, but how many years before a newhire could bid off a fleet (say the 757/767 fleet) and onto the 777 or 744 fleets should one choose to go that route? Is it 5 years? Regardless, you'll get some of the best variety possible.