Whenever I break one in...I like to use the oil that I plan on using for the life of the engine. Even if I plan on later switching it over to a full synthetic. Like if I was gonna use Valvoline, I'd use the non-detergent to break in the cam, then I'd use the standard oil until I got some more break-in miles/hours on it. I'd then switch over to the Valvoline Dura-blend, and I'd run that for awhile. Lastly, I'd make the switch over to the Valvoline Full Synthetic.
I have several distributor-driven oil pump shafts that I've extended and I use them chucked up in a drill to prime the engine before I ever start it up. I ALWAYS do that first and foremost. If the engine that I'm breaking-in doesn't have a good oil pressure gauge....I hook one of those up as well as a good temp gauge. These are the 2 most important things that I like to keep a very close eye on during break-in.
After you initially start the engine, you vary the rpm's for specific periods of time (minutes). This varies depending on the type of cam/head(s)/pistons you are going to be breaking in. I always drain the oil after this "cam break-in procedure"....which is a fairly short period of time.
I think there are MANY choices of good oils....but the important part, to me, is to ALWAYS run the same BRAND of oil that you started out with in your motor. Unless you experience some sort of a consumption problem with that particular brand of oil. Whatever you want to start with, is purely a preference issue, but I'd stay with whatever brand you started with for the duration.
Just about every mechanic that I've ever known has his own personal preferences, likes and dis-likes about this subject. It's really one of those "whatever works for you" things. Just like choosing your brand of motor oil is.
Aron