I'm sure there's a market out there, all the longer units I saw were literally 12"-16" units that sat on the floor., who the hell puts there TV that low.
I love the one I got, they came in 2 different lengths 1m and 1.5m, and you basically specced the legs/shelf supports to any length. So the Bottom one is slightly taller to allow for my centre speaker and the next 2 of 14" high.
I did run into a problem when I updated my Yamaha AV unit, it seems in the 10 years or so these units have got decidedly taller. I had the option of ordering some new supports, but felt it would then make my TV too high, so went with the Marantz slimeline AV unit.
I love all these so called AV units that have 2 or 3 shelfs at about 600mm long, don't they realise now a days most people have at least 2/3 units under their TV's.