Beef vs Pork Roast

My wife and I are doing a roast for Thanksgiving. We are trying to decide on what cut to cook. We originally were going to do beef, then some of her co-workers recommended pork. Then I pulled up an old thread on here where someone cooked a pork roast and a few guys said he should've done beef.

We basically have the cooking method down. Cut small incisions, stuff them with garlic, bell peppers and onions chopped finely. Also stuff seasonings in there and on the outside. We will start it at 11 pm at 175 degrees covered and crank it up to 325 for the last two hours (from 8-10 am).

What cut would be best for this method. I want it to be juicy and flavorful.