I converted my 2×9 to 1×9 over weekend on my Spec Enduro as I found that I didnt use the granny ring at all.
I use a 34t front with a 11-32 on back with all my standard XT/XTR stuff I already had. I purchased a Narrow Wide front 34t and away I go.
At some point I will go to a 11-34 on back when current cassette wears out but for my weekly ride and around Dalby over hols which doesnt have many hills I found that setup more than fine
Depends on what equipment you already have lying about which will help make a decision. I looked at that deal on Ribbles but felt it wasnt worth the expense of getting a 11-36 on back