Are you in charge of a big construction job?
If you are the head foreman you want the best commercial contractors you can find working on every project. The last thing you want is to hire inexperienced general and residential construction workers for any project you are in charge of. This is a mistake that will ultimately make you look bad if something was to go wrong.
For these reasons is why is it best to do an extensive research on all of the companies you are thinking of contracting out. I personally feel it is best to narrow it down to the top three companies first. Then to compare the prices and services offered between your top 3. Once you have the company that will best represent your name then you contact them and offer them the job.
Before you do hire them though make sure that they do have all of the proper permits. They will need permits to perform all of the design-build and constructions jobs that will be required.