I-65 south to I-85 north (Exit 171).
I-85 exit 9, keep to the right lane (doesn't stop) and head south on AL 271/Taylor Rd.
AL 271/Taylor Rd. ends at US 231.
We lived in the area for years (as a matter of fact we're in the area this week) and that's how we go. While your US 80 route would work (South Blvd.), the neighborhood isn't very pretty and there are a lot of stoplights along that route (I won't even get into Montgomery drivers).
When you get to Dothan on US 231, take the bypass to the right (western half) to get around town. Other than that, US 231 is smooth sailing through to FL (an occasional slowdown for a town here and there).