Of Course I may be biased, but I think a broker is your best choice. A bank has very rigid guidelines, and unless you fit into the whole perfectly, you will eihter not get approved or have a higher rate. While I am a broker, my company banks some of its loans. We use Chase Wholesale to do this, I can typically offer better rates than a Chase Branch could.
Nonetheless, you should do your homework. Contact a broker and banker and compare their products and prices. Make sure to ask for a copy of the Good Faith Extimate for reference.