This is a great question -- and I'm sure you'll probably save a lot of money by moving to Arizona from California once you buy that manufactured house. There is actually a big move afoot to help people get loans/mortgages so they can buy a manufactured home so your timing is good. Take a look at this article about Home Grants to find out more about loans specifically for manufactured homes.
Also, you might be able to get help from the Department of Agriculture if you area you are moving to is considered rural. One catch though is that you would have to be at least 62 years old, so you might have to wait a couple years. Or maybe marry someone who's 62? You can learn some more in Grants for Housing and you could also go directly to the USDA's website.
In the meantime if you want to learn more about benefits and services for seniors and ways you might be able to save some extra cash to save toward that home, take a look at Grants for Seniors.