Do a search of TDR, I'm sure you'll will find hours of reading about injectors.
To answer your question, yes, numerous companies make aftermarket injectors, but they are mostly designed for better/more performance. I do not know for sure of anyone building stock replacement injectors. I'm curious to know how they broke them, but thats moot when you need your truck. Like JR2stock suggested, I'd suggest they get some off a truck on the lot. Is this warranty work? What was wrong with your truck that required them to pull the injectors?
Jay