What about a M2 for a center it is only a few inches taller than the VP series.
I have tried pretty much all imaginable center channel configurations using M22s and the full VP series I own; 2 M22s on their side with tweeters on either end worked very well. The version you are speaking of with only one on its' side does not work as JohnK has indicated. I have run the VP100 and the VP150 in parallel, one above and one below with very good results as was a vertical M22 center quite good but very locateable.
If you must have only one center speaker and height is an issue I wouldn't hesitate to use either the VP100 or VP150.
