I needed to remodel my fireplace to make room for a TV.  I showed a picture and measurements to the salesman, Jimmy King, and he suggested a solution which was thousands of dollars less expensive than what I'd been considering (changing the wood mantle to a lower-height stone mantle instead of moving the fireplace).  He was able to speak knowledgably about heat shielding, building codes, certifications for fireplaces (the fireplace I'd found online was certified in the EU, but not the US, so I can't install it for insurance and permit reasons), changing to ceramic logs (rather than my old cement ones) to get more heat into the room, and was able to identify the manufacturer of my fireplace box from a picture I'd taken.  I could go on and on about the information he shared with me -- and he even said I could wait on purchasing the ceramic gas logs -- that there was no point buying them that day when I wasn't ready to install them yet and the price wasn't about to go up.  He is, hands down, the most knowledgeable fireplace salesman I've talked with!
A lot of other salesman I've encountered just want to sell you whatever product they're marketing and are pushy -- but Jimmy King wanted to help me know all my options and take my time to come up with just the right solution that would work and I'd be happy with in the long run.  He didn't seem to care at all whether that solution was the one he'd make the most money from or would get him a sale that day.  I have a lot of respect for his approach -- where he cares more about whether the customer is happy in the long term than pushing for an immediate sale.  (Ultimately, happy customers make referrals, so it is good business -- but he really made me feel like he cared about my happiness with the end solution.)
Bottom line: I don't find many companies or people that I'd recommend, but I wanted to take the time to recommend Fireplace & Grill Factory Outlet and Jimmy King.  Jimmy is the most honest, trustworthy, AND knowledgeable salesperson I think I've ever met -- in ANY field!
To top it off, they actually manufacture gas logs and gas fireplaces (which is why Jimmy was so knowledgeable about the certifications!), so I'll be buying local!!
The place may be kind of hard to find and may not look like much from the outside, but it is a hidden treasure!  Compared to the other stores I've tried, I don't think anyone else gives fireplace technical advice that is anywhere near as good.