Apple doesn't sell them, but Apple provides a list of AirPrint-compatible printers and multifunction devices here:
About AirPrint - Apple Support
The list isn't updated every day, so you may find a perfectly suitable printer/scanner that's not on it yet. If that's the case make absolutely, positively certain the device specifically indicates AirPrint compatibility. If it does not, then don't buy it.
Amazon is a good place to start evaluating options. Read the reviews and look specifically for reviews written by Mac users. They're usually among the more literate ones written.
Don't set foot inside a Best Buy, ever, for any reason. Ever.
Personally I have had good success with Brother's line of printers and multifunction devices. I have had the complete opposite experiences with HP.
And never, ever set foot inside a Best Buy. Never. Just don't.
(How on Earth is a 2015 iMac running Sierra an "older model???)