One thing to consider is not so much the equipment but the overall plan, which I gather is to show up somewhere and get a job as a DM or an instructor.
If that is the plan, you might find that a bit problematic. I don't think there are many places that are in need of DMs/instructors to the point that they will generally hire someone on that basis.
I agree with you entirely on this, as it stands the plan is to dive in Guatemala, Nicaragua and then Honduras, getting lots of experience, taking the DM and instructors course and getting to know lots of new people, dive shops etc - going to spend at least 6 months doing this and hope to have enough money saved so that I have time to get as much experience as I need while looking for a job.
The planning is a work in progress as not leaving until the end of April 2011.
Cheers
Other than the DM/Instructor and getting my Spanish up to a fluent level are there any other skills that you think are worth learning to add to an instructors CV?