Anyone have any go to stores/suppliers for kitchen backsplash and cabinet hardware other than HD or Lowe’s?

Even though you may be trouble shooting live with the GC while he’s on the line with a supplier, bouncing between options, politely ask for an email summarizing the approved product details.   

We are in the process of working with Home depot to get a quote but wanted to look at some other suppliers.

Roof loading, by hand or supplier charge to load.

Used the above to find a local mom-n-pop company and the bill was 1/10.mon-n-pop suppliers:  you know, their local with only one address.

You are essentially being the GC and keeping the project on budget and free of "shrinkage"(overcharge or theft).If your contractor is going to the suppliers for supplies they should be paid for that work/time via hourly rate agreed to for that task OR you can do COST-PLUS, meaning whatever the cost of supplies plus some agreed upon percentage that is added to the total to compensate for the time spent by contractor delivering supplies, this can get tricky if you don't know what you're doing, and contractors can exploit this too, if they are experienced and so inclined.

Not only are the big 3 here, but also suppliers to them and supporting industries.

Inventory near the new Apple campus is less than two weeks, and our eastern toll-road (130) is getting a nearly 4M sq ft Amazon logistics facility to the north (Pflugerville) and a Tesla assembly plant, with all the attendant suppliers, to the south, near the airport. 

As for your AC system, walk outside and write down the model number and the serial number off of the data plate.Once you get that done you can call the supplier of the type of AC you have ie.

My contractors have been using my menards card for years to buy materials and will also order from suppliers where I have an account.