Not sure what the speed limit is around your area, or how often, and how you drive. Most people seem to go by the 60mph rpm. If I'm taking my car more than 30 minutes, I'll be on a major interstate, which is 65mph, and of course everyone does 75-80mph.
Well 20mph difference also makes huge rpm difference. So in my case I went 3.73 because I have a double overdrive and 6th is .50. So with a 25.5" tall tire it puts me at 2000 rpm at 80 mph. Worked out awesome for highway cruising 700 miles one way to Kentucky last September.
Long story short. How fast will you be going in your commute, honestly?