Online mortgage lenders typically have upfront non-refundable application fees and poor customer service. You only want to apply with one if you know for a fact that your own cookie-cutter deal is a slam-dunk approval, and even then you're looking at 3-4 months with no communication until they call you in to sign the papers.
It's the biggest investment of your life. Expertise and high quality customer service are IMO worth paying a little bit extra for. Have a friend/realtor/financial planner/CPA/etc. refer you to a high quality loan officer to serve your needs.