A lintel is an angle iron and can come in many different sizes. Also you can put one on the inside of the house also.
Talk to a mason about the brick work and talk to a carpenter about the windows
This will save you money because like the poster above me said all a carpenter is going to do is sub out the brick work and then mark it up to make some money of the work.
Get references from any mason you use, you want the guy who is not intimated by the job also.