Never go for the biggest and most expensive house you can find in your loan range. Not only does this stretch your budget to the maximum, but it also will mean higher closing costs, higher insurance and typically a harder time to finance the purchase.
When considering a home mortgage service, consider the company as a whole. What do you know about them? In some cases, the mortgage you purchase will be sold to another company. This may not be a problem for you and it may not even be something you every need to know. Find out if it is a possibility though.