You can not put the telescopic CAR stock/bayonet lug/flash suppressor on a post 1994 AR, legally.
I have an Eagle Arms M4C, which has a telescopic stock, 11.5 inch barrel (with a permenant 4.5 inch flash suppressor to bring it up to 16 inches overall), and all the other nasties that make liberals gasp. It's proven to be a little bit finicky, which I think is a result of the shortened gas system. It cost $1100 new a few years ago and before the recent CA ban, I saw one for $2500 (probably just inflated to sucker some procrastinators).