REC

Each State has its own rules regarding insurance - specifically the minimum required liability insurance. If you have a rider on your Mexican insurance policy for U.S. liability coverage you should be fine. Each State "might" have specific rules on how long you can use your Mexican car but probably not a limit that will affect you. If you are going to be in the U.S. for many months it might be worth checking to be sure. For a shorter trip I wouldn't worry about it.

We have had several friends that spent time at Casa Nostra and we visited them often. They seemed very happy there and I was impressed with the facility and the staff. Since I don't have much direct experience with any of the other places my opinion is heavily slanted towards Casa Nostra. I would go there myself if and when the need arises. Good luck with your search. I think you have a number of very good options.

I go to Dermika - just next to Bugambilla Plaza where El Torito and the movie theater are. http://www.dermika.com.mx/#/

Here is a list of locations in Mexico from the Hollister/Mexico website. No idea about prices or if they can help you in English. I would be a little surprised if these supplies are cheaper in Mexico but perhaps so. Scroll down to Jalisco and you will find several places in the Guadalajara area that appear to sell Hollister products. http://www.hollister.com.mx/es-mx/wheretobuy Also looks like Amazon Mexico might have some of the supplies you are looking for. https://www.amazon.com.mx/s/ref=nb_sb_ss_i_1_7?__mk_es_MX=ÅMÅŽÕÑ&url=search-alias%3Daps&field-keywords=ostomia&sprefix=ostomia%2Caps%2C252&crid=2EMD57DS78TNC&rh=i%3Aaps%2Ck%3Aostomia