I would just put on a set of full Dual Exhaust with some interesting Mufflers.
It will not just sound a whole lot better, but will have a little more power and get some better gas mileage to boot.
Good approach towards your stated goals.
If you have a PowerGlide, you can noticeably improve the car's acceleration by converting to a manual transmission (a 3 or 4 speed). The car won't be fast, but it will be faster. Being able to choose what gear you want, when you want it, will improve the car's response to your 'commands'.
An auto with more gears also would be helpful, but I don't like autos on a car I wish to have some fun driving. That's just my personal choice that I am stating but not pushing.
My last comment is to make sure the car is always impeccably tuned.