I've never seen much point in tapped single-coils unless they're pretty powerful to begin with - so then the tap takes them down to something like vintage output. A vintage Strat or Tele pickup is about as low-output as I'd ever want to go, never mind tapping it - I'd have thought a tapped Mother's Milk would be pretty weedy sounding and probably not very useful.
Piledriver bridge and Trilogy neck perhaps?
There may only be certain models that are available tapped, although in theory any pickup could be tapped. Probably worth getting advice from Tim on this one.