I'm gonna do my Oil Change today, so yesterday I went to Toyota to get a filter since my WIX from Amsoil hasn't shown up yet and to get the washers for the drain plug.
Right behind me hanging up they had the oil filter wrenches. They had a 65mm which I was gonna buy since everyone on this thread has said it's definitely 65mm. The parts guy was suggesting using the 64mm because that's what all the tundras use I guess. I was doubting him, so he called the service dept and asked them, unfortunately no one knew because they have yet to do an oil change on the 5th gen 4Runner. I even had him look up the SST to see if there was any dimensions on that. There wasn't. I took his word for it and bought the 64MM.
A few minutes ago here at work, I went outside took the front plastic piece, then the skid as everyone has suggested, took just a few minutes. I stuck the wrench up to the filter housing and it fits perfectly.
So for everyone, a 64MM X 14 filter wrench is the perfect size for the Filter housing or at least mine, which should be the same for all 5th gens. It was $13.29 from the dealer and as you can see in the pics, the piece that attaches to the 3/8 ratchet is fully welded to the main piece.