Yes, you can bring your own pilots. They will have to train under the Part 135's training program, and abide by Part 135 rules when operating under Part 135. I believe you can contract out the maintenance to any facility with DOT drug testing, but ultimately, the Part 135 operator as to make the decision, but I'm not exactly sure how that works. Chapter 9 should answer your maintenance questions:
https://www.faa.gov/documentLibrary/...%20120-16F.pdf
Generally, you have to pay a set fee to start, absorb all of the training, maintenance, and operating expenses, and you get a percentage of the revenue after these expenses are taken out. I believe the standard is a 80/20 split between the owner and the Part 135 operator.