The question that you need to ask yourself, is if you want to travel alot. If you want to do industrial refrigeration, you will travel within your geograpic area, as there usually is not that much of it in a certain area. There is a very good book on industrial refrigeration called industrial refrigeration, by Wilbert Stoecker. This is about cold storage facilities, and recirculated ammonia. This type of system is always a built up system and not a packaged chiller. The book is not cheap, you will pay over $100 for it. This is not a PDF that you can download. Good luck in your choice and remember that ammonia is not for everyone.
T Stoecker's is an excellent book, packed with lots of valuable information. You might also look into RETA (Refrigerating Engineers and Technicians Association). They have lots of books, courses and educational materials. They also have a certification program and these days, if you want to do industrial refrigeration, most companies will want you to have a RETA certification.