I think you'll be happy with the GSII. Unless you're in a metro area, LTE shouldn't be a priority. It took AT&T nearly two years from the time it announced 3G and I bought a 3G phone until the service actually worked here.
To me, the horse race right now is between when they will activate LTE here and when they will roll out ICS for the GSII. I'm not holding my breath waiting for either, as AT&T's track record on both has been abysmal.