Our 22' did not come with any stabilizers, we didn't know enough to know they weren't there. Anyway, yes, you want good scissor jacks on the front and back.
I'm also going be be getting some stabilizers for the sides. We have teenaged boys, and when they move, it's like sleeping on jello.
As far as where to put them...someone else will have to answer that, as we had a shop do it for us.
2013 f150 Ecoboost 4x4
2009 Gray Wolf, 22BH