If you were going to be wheelin' a lot on iffy trails, I'd say invest in the 4 pointers. But for dual purpose, on/off road use and mild trails (which I think is your usage), the standard shoulder belt is a bit more "user friendly." I've got the 3 pointers in my 40 mounted to the roll bar and the tub.
1976 FJ40 - green and mostly stock
1996 FZJ80 - not so stock