A dealer is only going to put together what he sells, and what has good profit margin, also what is in stock.
Most of the time dealers do not really listen to your needs, they try to feed you what they want to sell. I've had dealers tell me my setup is crap, and not worth investing any time or money into. While trying to sell me a $10k amp, and a $6k subwoofer.
There are times, when someone will work with you, move products around, even let you bring in one of your component to see how it sounds with the other stuff.
Also found that synergy at the dealer might not be synergy at home. Took me a while to figure out that the room is one of the most important parts.