You should be able to get Mobil 1 at Pep Boys! My local one has it in all the delicious viscosities you should desire.
You can go to:
http://www.pepboys.com for a listing of a store near you. You can also buy it at Kragen/Checker/Chief, Target, Walmart, Kmart, and of course, any Mobil service station.
It really isn't all that mysterious or exotic anymore.
As to the "break-in" question, the service manager at my local dealer says that although they used to have a 1000 mile initial "break-in" period after which they would do a valve adjustment and oil 1st change, they have no information from the factory about the new engines being specially prepared, or "broken in" at all. they come with Mobil 1 in the crankcase, and do not get their first scheduled oil change for 10,000 miles. He added that they recently got a service bulletin directing them to only use Mobil 1 on all cars that come in for service from now on...