Your best bet is to check with agents specializing in mobile home sales, or escrow companies that process these sales. Also, be aware than some mobile homes can be registered with the DMV as vehicles, with different tax rates, while others are considered real property. It also depends on whether you own/lease the land, too.
The choices for mobile homes older than June 1 1976 are finance companies.
You may want to google mobile home financing and find the companies that do the financing.