The RS cars had V8s as well - the 305 carb and 305 TBI were available in the RS's (depending on the year). It's easier to swap a V8 into a V8 car than into a V6 car.
I love the T-tops, I just removed my A/C because I never run it as my tops are always out - others want hard tops as they are more into the racing than I am - the hardtop is sturdier, but SFC's are a must on either car. Stop driving in neighborhoods where the trees are jumping out into the road, and it won't be a factor anymore!
I prefer auto for 2 reasons - 5 speed won't handle a 350 motor and the T56 is out of my budget for the next few years, and I'm too old with bad knees to be clutching through town all day. It's easier to swap an auto into a manual car than it is to swap a manual into an auto car.
Good luck!