I'd stockpile them myself, but life keeps me from doing so. I'd go FJ60, but up here they want twice as much as a mini. And I never think about a FJ40. If they get too expensive, I'll look at getting a Ruff Stuff axle in a FJ60 width, for $600. That way I know that the axle is new and not bent and is somebodies headache.
I always get leary about people selling a axle housing cheap online.