I don't think you need the latest model..
Take a look back to the history of PS..
PS1.. never owned one so I can't say really...
PS2's had a slim and a phat version.. they ran the same games
PS3's had a slim and a phat version too... they also ran the same games
PS4.. well I gave up gaming so I don't know anthing about the next gen... But it's logical to think that any PS4 would do.
I sure do hope that the loading times are a lot shorter in the re-matered version...