The best answer is to do your homework.
Angies list will provide some reputable sources for your area but only you will be able to make an informed decision on who you choose by doing some investigating.
1. call several companies and ask for a quote over the phone based on the width, height, composition of door you are replacing or desire to have.
2. check reviews of the companies you are considering using.
3. check for complaints as well.
4. now have the company or companies you are considering come and show samples and give you an accurate quote so that you can make a complete and informed decision.