ha, i had the same problem this weekend. Changing plugs in a Mazda b2300 pickup (ford/mazda ought to hang the bastard who designed 8 plugs for a 4cyl. you have to remove the entire intake system!) my Ford mustang (still have to remove the intake to the butterfly) and my 750D (easiest to change!).
no one has the ngk's and I tried every parts store I could find.
Sparkplugs.com seems like the best source.
The bad news is that I called all sorts of auto parts dealers in my area hoping to find a plug that would work... no luck. I needed new plugs in a hurry, so I picked some up at my local dealer ($26 for 4 plugs). Yeah, I got reamed.
If you can wait a while, I would order from sparkplugs.com and save a little cash.