Nothing will give you more seat of the pants feeling of improved power like a change to deeper (lower numerically) rear end gears. You may have something like high 2's now (2:79, etc) and if you go to 3:50's it will make a big difference in take off power.

Pertronix is an excellent way to convert a stock point type dist to electronic. I can't remember, does your '72 have points or is it electronic already?

Reason I mention vacuum advance is that a mechanical advance can cause a street driven engine to overheat. You need the vacuum to cure that. Your stock dist is vacuum already.

As for parts, like intake etc. Get some catalogs from Summit, Jegs, Performance Auto Warehouse, etc. and start comparing. Edelbrock makes a performer series of intake and matched carb that will be perfect for your car. Dual exhaust or headers and duals will help the power also. About a 600 cfm carb would be right for a mild street 351.

You are asking some good questions.
Don