First of all do not go cheap. Get a handler. While there are several good handling companies out there, I would strongly suggest you deal with Universal. They are not the cheapest out there, but they are just about the only one out there that will make phone calls in necessary. And with a less than normal trip like this one, you will be better off.
Next. Make sure the insurance is set up for this trip. Mexico requires Mexico insurance.
Do not plan on making quick turns. Things take a whole lot longer than they do in the states, even with a handler. Also bring some company pens or hats with you. Plus even with a handler, you will need some cash so bring some with you.
Do not plan on trying to get maximum range out of the aircraft. Plus I would bring a hand held GPS with you as a backup, if you have panel mounted unit. Also I would give some consideration to wearing a uniform shirt and stripes. I realize that this is not the norm, however, everyone that works on the airport south of the Rio Grande wears a uniform with stripes, even the people cleaning the toilets. Without having a uniform, this will take much longer.
Have fun and take a camera with you. Wish I was going along.