The rule I followed when working on my '68 was that if there were better parts on the market that had a factory appearance I would use them. This was especially true for parts having to do with safety and reliability.
Since you drive your car regularly and will use the A/C, don't skimp on the cooling system. At minimum get your original radiator recored. It's bound to be on it's last legs if it's the original one. Next step up would be a Desert Cooler radiator from Ames. The top shelf would be an aluminum unit from Rodney Red if your budget allows. Find a water pump with a cast iron impeller - I believe Ames has these as well. Clearance the water pump dividing plate and the water pump impeller - see Jim Hand's book for more info on that.
Finally, if you are missing the factory 7 blade fan find one and buy a good quality thermostatic clutch for it. I have to be honest about this one. I changed back to a factory fan after running a flex fan for years and actually saw my temps increase. Most folks swear the factory 7 blade fans cool the best.
Other things you might consider upgrading along the way:
-Trade the points ignition for an HEI or electronic conversion kit from Pertronix or Mallory
-If you have 4 wheel drum brakes, consider buying a power disc conversion kit
-Upgrade your suspension bushings to polygraphite. This is more of a personal choice as some folks don't like the harsh ride polyurethane can give you.
-Upgrade to a larger front sway bar from a late '70's WS6 T/A
-Add or upgrade to a larger rear sway bar and boxed control arms
-If your A/C system is broken, convert it over to 134a when you get it working again. This is not as easy as it sounds and could be fairly expensive.
Other resources to check: the forums at the Performance Years website, back issues of High Performance Pontiac Magazine, classicalpontiac.com, and Jim Hand's book "Building High Performance Pontiac V8s"