I run Skys kit on my 85 4runner. I have had it one for 3 years now with no problems whatsoever. I also have upgraded to vented rotors and IFS calipers. You do need the IFS axel hubs as the mounting surface is further outboard then the non IFS axel hub. All the wheel bearings and bearing seals are the same as your solid axel hub, so its pretty simple overall. Oh and no the kit wont work with the SA axel hubs while you look for IFS axel hubs.
I like this kit over regular spacers as I wanted my rims to the actual hub face than a spacer then hub.