JBLM is a steady supplier of renters in my neighborhood.  

I also learned simply by spending time with suppliers, a lumber yard is like a candy store to a kid with me and my dad.

You'd do this through WREIAs primarily2- Another way, which is how I found 1 of my 2 main crews, is to call up rehab material suppliers.

I am looking for good providers/suppliers of Turnkey properties in the Charlotte market.

There is enough information from people who done it and advertising from suppliers that you can use to pull it all together and do deals yourself. 

Why not start a company of this sort and set up meetings with investors and discuss all that investors are looking for and services they would use, have listings of all open units, have maintenance people all set up and ready, have contractors that all of the investors get better pricing from due to high volume, also suppliers lower pricing.

For you, something in the line of, "I bought a new house, I didn't buy a rehab, will you accept a new material and your supplier gave you a used one?".

You may be able to get credit from some of your suppliers by also offering to personally guarantee payments.Building credit is a process and you will probably want to get a DUNS account to verify what your business is like.

Suppliers and skilled repairmen are likely going to be harder to come by out there. 

Find a reputable contractor who has a bank account in the name of the business(no checks written to their personal name) and preferably credit at Home Depot and local suppliers.