Area Code tryouts last summer (in Calif) were July 7th & 8th. Stanford Camp ends on July 4th so you can do them both. The biggest problem would be the USA Baseball 16U Championships as they back up to the Stanford Camp. For pitchers this is a problem. (which is one of the reasons we skipped the Stanford Camp last year as a Soph) The Headfirst Camp is usually just following the Stanford Camp which could be a problem, but I believe it is prior this year. I have heard it can be troublesome for a pitcher trying to do both the Stanford and Headfirst camps.
Like others have posted making the Area Code team is basically a ticket to pretty much any college you would be interested in. (I am sure TR or someone will pop in here on this statement...) I have heard that there tends to be a little more "politics" in choosing the teams now as opposed to when Bob ran them. They are free and the tryouts are still a great event even if you don't make the team(s).
I should also add that the Stanford camp is geared toward high academic players so if you don't fit this profile you should consider whether you want to go there.