Should I get a 360 motor/tranny

I think everyone should have at least one 360/727. So yes... get it.
I can't tell you how many drum brake, factory torsion bar cars we built with /6 bars. The difference isnt very much, and in fact the weight of the 225 is very similar to a small V8. Less than a passenger's weight. Improvements CAN be made, but most certainly don't HAVE to be made at the same time. You will have to upgrade the rear once the 7 1/4 blows up tho.