It seems like a lot of people who finance go directly through Disney. I do believe you can finance a resale purchase, but it is more difficult to qualify. We bought resale however paid cash, so I am not aware of the financing options and I don't see too many posts here about the subject. I'm sure even though you are not ready to buy quite yet one of the resale stores would be happy to give you some info. We had a good experience with TSS (see ad above on this message board).
Today in the mail I received an unsolicited offer for a personal loan from a credit card company/bank. I have already shredded it, but I do remember they offered 8.99% for qualified applicants. So a personal loan from a bank might be another option, possibly, if you have good credit.