Which state to form LLC in?
Since the property is located in Pennsylvania you need the holding LLC to be registered in Pennsylvania as well.
Technically you could register your LLC anywhere and then register it as a Foreign Entity in Pennsylvania, but in my opinion it is completely redundant (there might be a few small advantages for doing so, but overall its probably not worth the money and the effort).
So yes, in your case I would go for registering the LLC in Pennsylvania. Keep in mind that when you decide to sell the property you would pretty much sell the holding LLC with the property inside.