The Sinner in the bridge will be as hot as a humbucker, but it won't quite sound like a humbucker. It has a single coil sound, though not a typical single coil pickup sound--if that makes sense! :)
I have a Strat-style guitar with the neck and middle pickups very close to the BKP Mother's Milk pickups, as far as I can tell. The bridge is the Sinner pickup. With those pickups in there I can go from Hendrix sounds to heavy modern stuff. I can get all the gain I need from my amp.
For what you said you play, you'll be happy with the Irish Tours for neck and middle, IMO. The Sinner will give you all the kick you need, though it won't sound exactly like a humcker. So if you really want a humbucker in the bridge, you should buy one.