Ok I really wish the 912 forum would get as big as this 911 Forum but I don't think thats going to happen

I can't get any responses on anything in there. So maybe you guys could help me out.
I am about to do my first oil change in my 1969 912 and I have the filter and gaskets and stuff. But now it's time to buy the oil.
I need to know what weight would be best for the car? I drive pretty hard and rev the engine pretty high (in gear of course) so I need somthing that will hold up good and protect the engine. I am going to be using a Non-synthetic oil mainly because of the price.
I live in Kentucky so it never ever gets under 40deg Far in the summer here. And usually never gets over 90-deg.
I was thinking maybe 20w-50? Or do I need SAE30? I'm just really confused

this is my first air-cooled car. So help me out guys what weight would you use?
Thanks!