Simply, golfers hit it best with the club that fits them the best. The only way to assure that you are buying the right equipment is to be clubfit by a professional This is done by having the golfer hit identical clubs on the driving range with the only difference being the frequency and length of the shaft. The trained clubfitter studies the flight of the ball and where the ball flight begins. If it starts out right then the shaft is too stiff and vice versa. The process of elimination will bring us to the shaft that starts out straight.
Grip style is a matter of personal preference as opposed to size which can be crucial.
Some manufacturers use glove size as the determinant for custom grip size but this doesn't necessarily show the relationship between finger length and palm size. Only by fitting ones hand to a grip can we tell where the fingers meet the palm. Improper grip size can lead to tension, one of the most common errors in the swing. Standard lie and loft assume that every one is the same size and has the same swing. Loft has to do with the angle of the clubhead and lie with the angle of the shaft and clubhead.