PS4 for a novice

[sw15mum]

Planning on getting a PS4 for the kids for Christmas but I'm confused about the different memory sizes etc. If I get a PS4 slim is there much benefit in getting the bigger memory over the 500gb one. Am clueless so if anyone knows about these things I'd be grateful! (I know that for phones, iPads etc it's better but do I really need to extra on the PS4??)

More memory the better

I ran out of memory on mine after a year,so ds bought a bigger memory card and put it on

There is also a new machine coming out soon as well,