If the B767 operation is in Thailand BEWARE, I've seen the same aircraft in at least three different paint jobs in the last few years. A recurring series of start ups that fizzle out usually owing money.
B767 is getting on a bit now, the type rating will get you looked at and it is heavy time, but the A320 is definitely more marketable and you'll get a quicker upgrade.
I would take the secure low cost option, get an upgrade and save money to pay off the bond early if I wanted to move to the sand pit. You'll work harder and advance quicker, with 2000hrs of short sectors in an A320 you'll be very attractive to potential employers, 3000hrs and you are upgradeable. Plenty of jobs going for Airbus drivers.