a K2 would be perfect for effects imho and i want to get one as soon as they come out. should give u control over more than an X1, tho that is also a very cool controller. for effects i like my scs.3d’s esp as u have no issues changing layers, to control diff fx units, with full led recall.
It would help to know the software you are trying to control. The X1 is definitely going to be your best bet for two FX units and two decks in Traktor.
I use an AKAI MPD32 for my two deck setup.
Running Traktor SP2 with chained FX I have just the right amount of faders for the job.
Works a treat and has so many banks I can assign literally every other function to it as well.
Believe it or not using a Fader for FX actually feels better than a rotary IMO