Tomorrow I'm buying a 1978 CB 750. The guys says it will start right up but he doesn't have a battery for it. I want to bring a battery but it being my first bike, I have no idea what to get.
Go to parts store and have them look up the battery for whatever brand they sell. I would just get a cheap lead/acid battery because you have no idea if the bike is in fact runnable and no point in dumping a lot of money into a really good battery until you are sure the bike is worth it.