You really have a number of very good break-in oil's on the market, it's just a matter of choice.
I do recommend avoiding picking up any oil's from the shopping malls or the like!
(Add) I also recommend against adding any add'l addivitives, really unnecessary with the correct oil!
Thanks, Gary in N.Y.
P.S. Here's a couple we use, one is the Brad-Penn, which is mfd by the original Kendall oil from Pa. The other is the Lucas brand, also a decent oil. These are dedicated for initial start ups. Valvoline "Race" and Penzzoil 25-50 all work nicely also!