You're gonna be hard pressed to come up with a bolt on slider for the GX. I started out with those same intentions but after studying the frame and all the components tucked away it is nearly impossible to be able to get a bolt through the frame in all the locations you'd need to support.
I ended up just welding mine directly to the frame. If they ever need to come off, a sawzall will do just fine.
Do you think it would be possible to weld attachment points onto the frame and then still be able to take the sliders off (bonus points if you could put the steps back on)?
So, the gx470 is really that more convoluted than the 4runner even without KDSS? Just because of the AHC?
I have been on the hunt for bolt on sliders for a year now. I did contact the owner of Bud Built and he now is making sliders for the 120 style 4Runner. I asked about him making some for the GX470 and he would be willing to try but needs a GX to look at. I live in WI and he is located in NC. If anyone is near that area and would be willing to use their GX as a test vehicle please contact him at bud built.com. I would but way to far of a drive.