The only roller skis I've ever seen were for nordic skiing. There might be alpine ones too, but I've never seen them, and I've got no idea where to buy them from.
Check my blog for updates and reviews: http://aslansskiblog.blogspot.co.uk/
Joey -Formerly *III.JVD.III*
I post from mobile the majority of the time, so if the above is incomprehensible, I apologize.