Upload & Sell: Off
If you are flying into Mexico City, after you go through immigration you pick up your luggage and go through customs. There you press a button, if it's a green light they let you through without checking your luggage, if it's a red light they go through everything.
I think my family and I, from going into Mexico maybe 20 times, have had the red light only twice. Also, you can take a lot of personal stuff. I'm trying to find the page where it says exactly what you can take as personal items, but I know it's rather generous. This is of course if it's PERSONAL items. If things are in boxes, with manuals, etc. You will probably have to do a lot of explaining and end up paying, for they'll think you're trying to sell merchandise.
Anyway, 3 weeks ago I went with 2 gripped bodies, a 300, a tilt shift lens, 135 f/2l, 85 1.8, 50 1.4, and 28-135mm, as well as a tripod, and they did not seem to care. You are bringing more equipment (lights), so it may be different then.