A/C compressor and freon ?

[Daves72'GMC]

I'm almost done restoring my 72' GMC 402BB and it's time to recharge the factory A/C which was blowing cool air before the restoration. My ? is I've put new A/C hoses on and was wondering if I should charge the system with R-12 or freeze 12? and my other ? is should I replace the origional A/C compressor with a rebuilt one before I spend alot of money recharging the system or should I use the origional one and take a chance that the origional one is fine and charge the system? Thank you for all of your help.