Well make up your mind about software first.
It is not that Traktor is the end in all software, there are many other software products that are used to great success. Personally I use Serato DJ, there is VDJ Pro etc.
The workflow and how you DJ is different with each software so that is what you should make up your mind about.
Then of course you can get an advanced controller, but also the S4 is not the “end of all things”, there are other high ends like the DDJ SX (Serato), 4Trak (Traktor), VCI-400 (pretty much all software),…
The thing is that such a controller can be a bit overwhelming for a beginner, but if you are not easily scared it is also an investment for the future as you are unlikely to grow out of it quickly.