I'd like to provide a helpful response, but I do not understand what you are asking.

Is your contractor/designer doing the kitchen design, and supplying the cabinets and countertops?

I think you need to ask this contractor what their business model is and how they normally do things. We are design/build and we would handle everything, including all purchases of materials. Some contractors allow consumers to purchase their own products but keep a close eye on it. Others let consumers do what they wish - and this is generally where disasters happen because there is no coordination.

I just wasn't sure if I came into the experience with a plan already established - what materials were being used and where the materials were coming from. Or, if it's okay that I ask them to research the cost of granite vs quartz, or stock cabinets vs custom cabinets. The contractor is helping with design as well as supplying cabinets and counters.

FYI contractors are rarely designers so be aware that the kitchen could be a lot of what you don’t like.

Prior to starting any project, you may want to have everything selected with all pricing approved by you, the client. I believe this is what you are asking for? The layout should be designed and the following things should be selected: Flooring, countertops, cabinet quality level, door style, millwork style (if any), backsplash, all appliances, plumbing, and lighting, not to mention colors and finishes of walls and cabinetry. It's good to know what you are getting and know what is expected. I usually have a packet that outlines the process and explains timelines, including what goes on in the background. It's not a question of will it look good but a declaration that you are certain it will be functional, safe and be what you expected. Right at the beginning. The image I posted is of a current design for a client. Besides the backsplash, she knows what she's getting, cabinet dedication, appliances, countertops and storage space as well as electrical. They get all of this in BluePrint format with extra copies for the site and contractors. All of this is done before tear out begins and pricing is approved by client. If not, we aren't moving forward until we finalize the layout and selections plus pricing. I hope that helps?

I would ask a few more questions... is there a showroom for you to go to ? Will you see renderings of the kitchen layout? Will you get to see actual samples of your door styles/finishes? I work with many contractors as well as having in-house installation and everyone is different. Some contractors purchase all materials ( based on your approvals ) so they control quantities, delivery, correct material, etc. Others will just send in their client and we help them through the process and do the scheduling etc. The layout of the kitchen should always be done by a kitchen designer no matter what type of contractor/builder you hire.