Here in Northern California we have Pick 'n Pull, basically an auto recycler, you tell them what part you are looking for, they will either remove the part for a fee from a vehicle with the part you need, or you can go out and pull the part yourself for a much lower fee. There is likely an auto wrecker/recycler near you, I'd try there.
As for installing the oil pan, just pick up a Chilton book at a local auto parts store, always good to have around in case something else needs to be repaired.