Your own PICC Company...it all seems so complicated...but I'm muddling through it

So i have the LLC, the website, the equipment and supplies picked out, the services we will be offering, protocols/policies written, but I am abit unclear on how to proceed from here. Let me start by my limited understanding of what is expected as far as billing goes. They SNF or LTAC is responsible for all treatments related to that DRG. Billing is usually done through the pharmacy. With those SNF or LTAC's associated with large pharmacy chain such as PRN or Pharmerica, it is actually they who the service is billed to. then in turn they apply that cost to the facility. With smaller or independently owned facilities, they are responsible for the payment of the service directly. Meaning that a "Mobile PICC company" does not deal directly with medicare/caid or insurance companies. Knowing this does the PICC company have to:

1) become a certified medicare/aid provider
2)Itemize their bill with the appropriate codes, i.e. Insertion of non-tunneled venous catheter, ultrasound guidance.

Also for all those who own or have owned a picc co. where/who would be a good resource to gain some inside baseball knowledge from?

Another question who do you approach first when dealing with an LTAC or SNF. The Admin, DON, Medical Director, all three, none of the above?