Interesting comment on the axles. I drove 7-1/4" rear axles in 3 cars for over 200k miles and I don't spare the aggresssion on the throttle, and never had a lick of rear axle trouble. I suspect those blowing them are doing something hard or are starting with used ones from the j-yard that had problems to begin with. A good 7-1/4' should take a /6 no problem. You can get the large bolt pattern in all 3 axles.
The comment about the lighter rear axle is for keeping unsprung weight as low as you can for rough surface handling; live rear axles are never great but adding more weight makes poor handling worse. The brake and LBP swap all at once DOES make sense.
I am in the Appalachians and rough surface handling and handling in general are important if you drive on the roads rapidly from A to B. All of this info is suggestions and ideas and IMO, the OP should decide what he will use the car for; if all the roads in his area are very smooth, then the lighter axle wieght is of little value.
I don't see an issue with a manual floor shift trannie for DD.....?? If you are not drag racing, the manual will be a lot better aggressive driving trannie; the ability to use the rear braking of the engine through a manual in a RWD car will allow you do things in throwing the car about and taking advantage of weight transfer diving into corners that you cannot ever do in an auto (unless it is one of the new Challenger auto trannies). If you have raced a manual trannie car, it becomes obvious.
But, again these are just ideas and highlighting different aspects of performance and you get to make the decisions. I just like being able to keep up with a Porsche in twisty mountain roads; the look on their faces at the first stop when you have literally run them down in your better HP Detroit iron with the good handling package is priceless!
