Nice start. You have to make your own Rub. Most of the stuff is probably already in your cabinet and you control the Salt. Most commercial rubs are LOADED with salt because Spices Cost, Salt Don't. Check this out and add anything that you may like including adjusting the heat...
Try this... It is Mild and compliments different style sauces well...If you want spicier increase Blk Pepper to 1T and add 1T Wht Pepper and 1T Mustard powder. The Foiling Juice, at the bottom, makes a Sweet Finishing Sauce/Glaze for anything Pork. You can add 1/4C Ketchup, 2T Cider Vinegar and 2T Mustard to make a more traditional KC Style BBQ Sauce....Anything else, just ask...JJ
Mild Bubba Q Rub
1/2C Sugar in the Raw (Turbinado)
2T Sweet Paprika (Hungarian)
1T Kosher Salt
1T Chili Powder (contains some Cumin and Oregano) Ancho Chile is same without cumin, oregano etc.
1T Granulated Garlic
1T Granulated Onion
1tsp Black Pepper, more if you like
1/2tsp Grnd Allspice
Cayenne or Chipotle Pwd to taste, start with 1/2tsp and go from there.
You may also like this for Ribs and is a tasty Sweet Finishing Sauce...
It says Pork Loin Roast, is this a bone in loin roast or boneless. It looks really lean in the pictures, I hope it does not get tough or over cook for you. If it is a loin roast you may want to take it off now and foil wrap in towel and cooler and slice for sandwiches.
I pulled/chopped the meat and we made sandwiches. My wife and kids loved it. It was a little dry, but the taste was great. At the point you added BBQ sauce it was all good. I ended up throwing some bratwurst in the smoker too and they were the real hit of the day. I gave one to a friend of mine that stopped by the house and he said it was the best he had ever eaten.