VCI-400 can now be used as an external mixer with a firmware update, I think it is your best bet but the jpckey 3 is also pretty good if you only want two channels, the only shortfalls of the reloop are the cue buttons dont have the best action, there is a big click which delays the trigger unless you smash it down, and the led rings around the encoders are hard to see unless you are high above the unit. In saying that everything on the reloop is high quality which can’t be said about the S4.
I agree that the denon is too small to be used properly.
Traktor is retarded when it comes to jogwheels I’m not sure why they are so exclusive in their support, but the jockey 3 and the VCI-400’s jogs work perfectly in vdj with a small tweek of the registry if you ever choose to go down that route instead.