I have never seen the support pillars listed on any of the repair panel websites. I ended up making my own.
I bought 16ga wall, 3" square tube and cut it in half long ways. Then you end up with 2 pieces of "C" channel that is 3" wide by 1.5" sides. Then I cut the sides down to 1" and tapered it back out to the 1.5" at the bottom where it hooks to the floor.
1 3' piece will do the 2 struts like I described for under the hinges and use the other half to do the 2 struts back by where the seat belt retractors are behind the seat.
This is how I rebuilt mine.
'87 YJ, 4.2L built and bored, 8.5" of lift, 8.8 rear, AX15/NP 231, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...