I'm assuming that this is your first foray into the world of hats, if so I think that it is very important to be fitted by a professional. Go to a real hat shop that has an extensive inventory that will allow for the best fitting hat considering your face, physique and coloring.
If you get down Southern California way, be sure to check out Baron's California hats in Burbank. They have a decent inventory of RTW hats and do excellent custom work at reasonable cost. I am wearing a Baron's fedora that they custom made for me as I head for home this evening.
Just a postscript to the above: I would advise shunning The Village Hat Shop at all costs. I had the worst retail experience of my long life there! I finally packaged up a defective hat I bought from them and shipped it back to them with a nasty letter. I would rather die of exposure or sunstroke than deal with The Village Hat Shop again.