No need to go 1x11 just go 1x10. You can get a standard 36t cassette if not already and if your legs are still too weedy you can get a range expander to drop a cog and add a 40 or 42t ring on the cassette. You might need to mod the rear mech but theres long bits for them readily available.
If you did go 1x11 your needing new rear mech, rear shifter, cassette and more than likely chain. Also depending on crank and bcd could need new cranks to fit a ring of your liking.
If you did go 1x11 your needing new rear mech, rear shifter, cassette and more than likely chain. Also depending on crank and bcd could need new cranks to fit a ring of your liking.