There’s more flexibility in wheel/frame/forks mixing and matching than most realise.
The bottom bracket drop is the critical number if you’re going with smaller wheels. On a hardtail I’d say that the sensible limits of lowness is a 60mm BB drop with 27.5 tyres, 80mm drop with 29 and 47mm drop with 26. If you choose a 27.5 frame designed for a 150mm fork you’ll get the same angles with a 160mm 26 fork, and just the BB height 12.5mm less.
So ‘low’ is easily achievable by putting smaller wheels on a frame. Long is harder, especially if you want a steel frame. Bird, Whyte, Mondraker and Orange are making the longest hardtail frames I can think of. I noticed the new versions of the Switchback Ti will be in normal and longer sizes, which are 24mm longer than the current medium and large frames.
I’m riding a Bird Zero AM with -2 deg headset and 130mm fork and 27.5 wheels – that’ll give it a similar BB height to if you used 26 wheels, your 160mm fork and a standard headset on the same frame. Rides great and I’m not noticing extra harshness from it being alloy rather than 853 like my old frame.
