We have a local-ish sauce company called John-Tom's. It's a family business that uses their grandfather's old sweet red sauce recipes. We always get their medium-heat variety, called "Sneaky Hot." I actually tend to mix it 50/50 with a nice NC mustard-based sauce like the one City Barbecue sells.

BTW, if anyone is interested, John-Tom's sells over the internet in lots of 4 bottles each, and you can mix and match them.

I used to use a tomato-based sauce, but a couple of years ago I moved to my version of a mustard-vinegar sauce. This involves cooking my pork shoulders in or over an oven dish, as I feel the juices are too valuable to go down the drain. While the pork is resting, I pour off the grease, and deglaze the pan with cider vinegar - it is amazing the amount of piggy goodness that you get out of the sticky mess. Then I thicken with mustard powder, stir until completely smooth, then add either English (alcoholic) cider or apple juice until the sauce is the right consistency

Pull the pork, mix in the sauce, and then let it spend the night (at least) in the fridge, to come together, before reheating and serving.

This probably all sounds like heresy, but it results in great tasting pork, and no worry about when it will be ready. 

Nicely Done Chris.

I used to use a tomato-based sauce, but a couple of years ago I moved to my version of a mustard-vinegar sauce. This involves cooking my pork shoulders in or over an oven dish, as I feel the juices are too valuable to go down the drain. While the pork is resting, I pour off the grease, and deglaze the pan with cider vinegar - it is amazing the amount of piggy goodness that you get out of the sticky mess. Then I thicken with mustard powder, stir until completely smooth, then add either English (alcoholic) cider or apple juice until the sauce is the right consistency

Pull the pork, mix in the sauce, and then let it spend the night (at least) in the fridge, to come together, before reheating and serving.

This probably all sounds like heresy, but it results in great tasting pork, and no worry about when it will be ready. 

Being incapable of original thought, I got this recipe from some website somewhere--probably PH.  I would give credit if I could only remember the source.

1 Cup Apple Cider Vinegar
2 Tablespoons Brown Sugar
1 Teaspoon Tony Chachere's Creole Seasoning
1 Teaspoon Coarse Black Pepper
1 Teaspoon Red Pepper Flakes

Warm the Vinegar up enough so that it dissolves the Sugar well. Then add the remaining ingredients.

Thanks for all of the great suggestions. I've decided to go with three sauces. 1.) A mustard sauce similar to the one recommended by Maineac and Kristin. 2) A traditional commercial sauce such as the one modified by DK. 3.) Bentley's apricot and pear reduction.

I intend to try Bregent's vinegar finish if time allows since it was also highly recommended on various web sites.

Chris- I have always prepared my pulled pork similar to your description. The most significant difference is that I do not add dry mustard. I smoke my seasoned butt to slowly to an IT of 160°, place in a pan with some apple juice, cover with foil and cook to IT of 205°. Pour off all juices into a 1 qt. measuring cup and let the butt cool in a covered ice chest. Place the juices in the freezer until the fat has solidified. Pull the pork, remove the fat from the juices, reheat the juice and add back to the pork to obtain optimum moisture. I will definitely add dry mustard the next butt.

Why do people remove the fat from the drippings before they remix with the pulled pork?

Made it to the semi-finals, gotta love it!

I like to use it for biscuits, that is why I do it!

Why do people remove the fat from the drippings before they remix with the pulled pork?

if you don't eat the entire shoulder while warm, the orange congealed fat can be unappealing. 

DK

Why do people remove the fat from the drippings before they remix with the pulled pork?

The reason that I do it is to keep the (artery clogging) fat content down in the finished product, the cooked butt still has lots of residual fat for flavor. 

OK...so only for health and cosmetics.  I keep the fat juices for flavor.  Hopefully, my meds flush it through my system so it doesn't stick to my arteries.

Why do people remove the fat from the drippings before they remix with the pulled pork?

For me, it is because I usually refrigerate and reheat the next day. As a result an excess of fat tends to form in lumps on the surface.

Note that I don't get rid of all the fat, just the majority of it - also it is only the fat in the pan, there is still plenty of fat content in the shoulder itself.