Several popular home electronics outlets
A while back I had two zones in my house for A/V, configured via a cheapo Chinese HDMI switcher that allowed two zones to have any one of four inputs. This allowed me to watch my sat / PS4 in the kitchen whilst the missus could have BAke Off etc in the main room. Worked a treat, domestic bliss ensued.
Queue my amp blowing up and me thinking my shiny replacement needs these two independent zones built in. A bit research online was more difficult than it should have been so leather was trod and I hit the high streets. An all too common interaction went along the lines of;
Them - 'Can't be done mate'
Me - 'Why's that then?'
Them - 'You need a distribution amp as HDMI can't work over those distances'
Me - 'But I'm doing it now. With a cheap 10 quid box and a 12m HDMI cable'
Them - 'Nope it won't work. Besides those amps don't exist, both zones have to use the same input'
Suitable amp eventually tracked down and installed, all worked a treat (and continues to do so today over a longer run again in the new house).
Honestly, so many places and not department stores but so-called specialist AV showrooms, the names of which would be well known by those on here.