Love what you're doing. Congrats on diving in! As far as the a/c goes, I'd consider running it. My wife and son's ride with me all the time. They love ripping around in the 69 almost as much as I do. Living in an a/c world and with the humidity in VA, it would be nice to have it sometimes. Unfortunately, like has been mentioned, it will really detract from the rest of the engine bay and from the look it sounds like you're going for. That'll end up being a completely personal choice.
I'd be inclined to leave the heads aluminum. L89s had them raw aluminum didn't they?
You can get the "Caution Fan" sticker, NOS, at
www.losersrus.com. lolol...