You will not find it in Mexico, period.
I feel your pain on the Airlift, total junk. Mine also failed a bunch on a trip to Panama. I even had a 2nd set of Airlift bags shipped to me in Mexico when mine failed and those failed me too! If you have holes in the air bag you can plug them up with tire plugs. The plastic top cap on the air bags will break and have sharp edges, I suspect this is what has happened on yours. You can take the air bag out and clean up these edges and make them smooth. This will reduce the chance for more leaks a lot. If the air bags are not repairable...
I strongly suggest buying some Firestone air bags made for your truck or for the 1st Gen Tacoma, ie up to 2004. They are 10x more buff then the Airlift and have a much better mounting set up. I put these on my truck for the 2nd trip down to Panama and had zero problems with them.
Getting new leaf springs and shocks shipped to you in Mexico will be very expensive. I am not familiar with a 95 4Runner but is it leaves or coils in the rear? Shipping Firestone air bags down there won't cost much at all. If they will not ship directly to you have a friend or family member forward them to you. If your shocks are toast you should be able to find some that will work locally, or simply get some shipped down.
I do not suggest you have local springs made or sourced and fitted. These will be low quality and not designed for your weight. If you are on a long trip and your truck is heavy this will only cause you more dramas down the road. I strongly suggest you buy the Firestones, install them and forget all about your problems.