FYI Mazworx makes a weld in S chassis 6pt cages now for 385$. The main hoop and harness bar are already welded, but you have to put the rest together. Its a cheap solution for anyone wanting a cage that has a welder or knows some one with one.

U-Weld Roll Bar 6 Point Nissan S-Chassis

It comes with door bars and for an extra $100 you can get a rear X-brace. I'm betting you can swap out the door bars for the X-Brace if you call them.