The turntables would just be for “feel” of turntables, you would not use real vinyl music on them, but timecode vinyl. Those are specific vinyls with timecode for computers on them, that will show the software where you are and what you are doing. The whole thing is called DVS (digital vinyl system).
If you are already settled in your mind on the S4 and Traktor go for it, but I cannot see that you are already in such a stage.
I would rather go for something way cheaper (like a mixtrack pro) and learn stuff, try different things etc. and then possibly a year from now, you can make yourself an educated decission on what to get next.
Yes this would mean that will buy twice (as the mixtrack pro will be obsolete when you buy something new), but the mixtrack pro used is selling like hotcakes on ebay for quite a nice price, so you will not loose too much value or you could always keep it as a backup controller.
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