Thanks,
I already ordered a narrow wide chainring that will work with either the 10 or 11s whichever I decide to go with which will fit on my existing crank. Whichever group set I order comes with a shifter, cassette and new chain for the given speed.
I took off the old 9 speed cassette yesterday and there was no spacer behind it.
I know when I updated my roadie that shimano 9/10 speed are compatible on the same hub, but when they switched to 11 you had to get a new hub and was just trying to see if anybody had some experience with this in the MTB world as I am a complete newb to MTB.
As far as gearing I am not worried. With a 30t chainring and a 42t cassette I have essentially the same low gear as on the 24 front 34 rear currently on there.