I have some experience with what I think the OP is asking, and the courier industry now is about 5% of what it was 20 years ago - the internet basically did it in.

My sis-in-law was regional manager for one of the bigger courier companies, one that specialized in the entertainment industry and legal documents. Back in the day, one of their staff would go to a film shoot, pick up a reel, go to the airport and then personally fly with it to whatever studio or network exec was supposed to review. These days they just email the file instead. When I was making regular transcon trips in college I would sometimes pick up a package at one end, carry it on the plane, then hand it off to a local company employee at the other end. Again, those documents are going electronically now.

There are only a very few companies left that transport high value small items, and their prices are outrageous. Personally I'd try DHL over the tiny firms out there.