Dreago. You are buying a house, not a car. Just find one company and stick to it. That person is going to spend a lot of time and money on you. Put the shoe on the other foot.
If you still don't care, then look at it this way. The builder is going to be more lenient on closing if you use his/her lender. Make sure you get something in writing from the builder that if the lender takes advantage of you, you have the right to go with a different lender and/or get your earnest money or deposit back.
If you take the chance of going to a lender that does not work with the builder and that lender screws up and delays the closing or can't get you closed, you may lose your money. Are you willing to take the chance?
What you need to do to save yourself much effort and time, is to get good faith estimates from all of the lenders that you are looking at. All GFE's have the fees in different catagories. The 800 series catagory is for lender fees. Lender fees can not, by law, be anywhere else on the GFE. All of the other catagories will be the same for all lenders, title, escrow, home owners insurance etc. Add up all of the fees in the 800 series of each GFE and see who is the lowest. Once you have done that and you narrow down your search to decide who you will be working with, hang on to that GFE and take it to the closing and make sure none of the fees have changed with the lender you have selected. THe GFE is one of your best weapons against bait and switch. Beware of lenders stating that they have the lowest rates.
In addition to rates and fees, it would be an good idea to work with a lender who is local and you can visit face to face. An online lender doesn't care if you are "happy" or not. They want your money and the loan closed so they can move on to their next deal. A local lender has their local reputation to protect. Good luck