Trulia is not a mortgage company or real estate sales company, it's a website with a number or pros participating at various levels.
The rate you get will depend on more than just your credit score, although it's a big part. Find a great local lender to consider. One that does FHA may be a good option for you. Another option for Mobile Homes are Portfolio Lenders, often regional banks may be open to financing a Mobile Home.
Please realize that mobile home rates are typically higher and harder to get. In general mobile homes are not considered good investment that appreciate the same way that a conventional stick built home does. On the other hand, they are much less expensive to begin with, so they serve a purpose. Best of luck.