Ball python enclosure questions

[Knightcliffe]

So I am looking to get a ball python for my first snake and have been doing some research but have gotten conflicting information when talking to people. Most of the research I have done says that I need a decent humidity (about 60%) for my son to be pet but when calling around trying to find a good tank I talked to a guy that said it wasn't important that all I needed was a good water bowl, also that a screen top was good but I read that I shouldn't get a screen top tank as it can't keep the humidity up very well. So I'm just wondering if the guy is right or if he was just giving me crap advice hoping for some sales.