For what its worth a steel long travel hardtail will not be much different from a long travel alloy bike. Stick some 140mm forks on a Stiffee. It wont be any different from an 853 tubed long travel hardtail.
As said above get a bike that needs a longer seatpost and longer top tube, use a shorter stem. 27.2mm seatpost size, Titanium seatpost. All things that I have found make more difference to the ride quality on the back end.
I reckon this steel thing is just a throwback to the days of a pencil thin tubed Kona Lavdome with 0 travel rigid forks and 1.8 XC tyres. Things have changed, Massive fat tyres, massive travel forks and steel frames with beefed up joints and seriously fat tubes and thicker butting to the tubes. The above things will make more difference. It seems none of this has been taken into account and steel frames are like riding beds of air if you believe all whats said, which they aint!