Novation Twitch or Traktor S2 for trance mixing

I would say Yes they are both good for your purpose but you might benefit from using Traktor instead of ITCH
(or the other way around as ITCH is more easy to get started with)
You need to ask yourself what software to use and then look at what controllers there is that is good for that software.

If you come to the conclution that you want Traktor (as it is the most common) there is NI S4/S2 Denon MC6000/3000
And the new Numark 4Trak that is in the top segment IMO

Itch is Numark NS6 and Twitch
(wich I personly don’t like because the lack of joggs but that is my oppinion the quality is good)