As Zarak pointed out, the idea is to get the tweeter at about ear level. I have fairly low furniture, so I went with the (17") Plateau M-17
. I've been pretty happy with my decision, except that the top of the stand is a bit too wide for the M22s and thus looks a tad goofy. Oh well.
I recommend sitting in your listening position and measuring the distance from the floor to your ear. Then, subtract about twenty inches for the M22. The remaining number is the approximate height of the stand you want to get.
And be sure to take the base dimensions of the M22s into consideration. Don't make my mistake!