My current XC bike uses 29x2.35 wheels, 185mm crank arms, 26/36 and 11-42.
I find the 11t cog to be useless like on most other bikes, unless the front chainring is seriously undergeared for the riding you are doing. Maybe a 26/38 or 28/38 with a 13/42 cassette (if that even existed) would work better.