Your advice is spot on.  The only thing I would say is 20 is too much.  To me, maximum of six.  I have held only 4 stocks for 95% of my portfolio for over 10 years and am getting 15% per year return.  I finally sold the remaining 5% hodgepodge because, while they did ok, they didn't do anywhere near as good as the other four.

My top picks: V, MA, BP (for div), RDSA (for div), APPL, GOOG, AT&T.  I only own the first four, but I really like the others.  The ones you posted are great picks too!