Back when I was the guy who helped all his friends with their car work (late 70s early 80s), I had Grampa's Champion Flex head ratchet CT-405 with a finger spinner, a 3" extension, and a Champion Plug Master socket CT-407 stuck on it. With just that, I could do 90% of spark plugs. A '68 Mustang GT with a 390 required a set up with 2 swivels and 3 extension, or so the professional mechanic told me. I could not reach the driver's rear plug with everything I owned back then (1 swivel, and 1 extra 6" extension.
I have not changed nearly as many plugs since them, but I think that same rig would work fine on my '06 Tacoma, 4.0 V6, as I have a mechanic change them now.