The problem with out of country skin removal surgery would be the after-care, I think. Unless your mom would want to stay out of country for six weeks or so, she would probably be better off with a local doctor for follow-up visits, questions, stitch and staple removal, and dealing with any complications.
Is there any chance that your mom might get insurance coverage for the skin removal? Is it causing her medical problems, such as rashes and infections?
As for financing, most plastic surgeons have payment plans or work with finance companies that offer payment plans. They understand how difficult it is to come up with that kind of money up front! My suggestion is to find a doctor based on his reputation and references, just like Witchy said, and then be frank with him or her regarding your mom's finances. Ask the doctor or office manager to help you figure out a way to make this work.
Best of luck to you and your mom!