Jeremiah Proffitt just opened up his new shop, give him a call and see if he will sell you the rear 4 link kit he used to make. It was specifically for the fj40. As far as your steering is concerned, I see you have the super beef in the knuckles and tie rods. However this makes the sector shaft the weak link. A broken sector shaft on the trail would be a nightmare I would not want to face. If you did hydro assist then I would think that would relieve the sector shaft from stress if you bounced into a rock hard or something. I kept my relay rod stock, but tie rod is beefed up, so that if something happened the relay rod would bend, in which case it would just affect lock to lock steering but not toe. I could bend it back somewhat straight and hopefully get home without much issue.