The advice below is good generic advice. But it doesn't answer your question.
Here's how to find a land-lease contract: http://bit.ly/findaleaseoption
That's a blog I wrote on how to find lease-options, rent-to-owns, and similar situations.
The tie-in with the advice below is that during the time you're doing a land lease or lease-option, you'll need to clean your credit up. And you have to be committed to doing so.
Hope that helps.