well, if you want to learn more about the 240SX, this isn't the best place to start. where you want to go is the 240SX.org forums or
www.nissaninfiniticlub.com
let me ask you. what are your plans front end wise, if you have any at all. because the USDM S14A is the same as the JDM S14A and the USDM S14B is the same as the JDM S14B. so you don't have much of an option, lol. the difference in the two styles is very minimal. the differences are the headlights, shape of hood, and shape of fenders, as well as frontturn signals and all that, but that's not much to worry about.
S14A has the round/circular headlights, i forgot the exact name.
S14B has the "angry eye" look, zenki, i believe it was.
i don't know of any shops in Ohio, so i'm not much help there. but shops here in CA (if you don't mind having it shipped to your door from out of state) would be AfterDark Tuning (one of the guys/moderators from the NICO forums started that company), Unstable-Hybrids, RollHard, and Phase2MotorTrend, to name a few.