if you wanted to mount center, why not buy a symmetrical ski?
doing what you want to do is like buying a corvette, and then saying, eh, i think i wanna use it for off roading.
buy the ski that does what you want it to do, not buy some old ski and then mount it where you please. thats counter intuitive and just pointless, you wont ever get the performance that you would out of a symmetrical ski.
my 2 cents.