You want to look for small local banks that specialize in owner built homes. It might depend on the area of the country you are from, if it is more common in your area for people to do it, then they will.
Most don't require money down, and instead base the loan off the final appraisal value for the property instead of the cost to borrow. It is generally a 80/20 or 70/30 where they will loan you 70% of the final value.
