Are you looking for a hardware sound module to use with your Roland controller, or software sound modules-- soft synths and other virtual instruments?
I think there were two versions of the DJX-- the DJX and the DJX-II. Both had MIDI IN/OUT ports, so you could certainly hook a MIDI controller to either one. But they're both older models. Is there a particular reason you asked about the DJX-- for instance, does someone have a used one for sale near you?
Likewise with the Optimus TD-1150. It has MIDI IN/OUT ports, so you could hook a MIDI controller to it.
I have no experience with either DJX model, nor with the Optimus. However, if both were available near me to buy used, personally I think I'd go for the DJX, because from the owner's manuals it looks like the DJX has more voices and twice the polyphony of the Optimus, and it also looks like the DJX responds to MIDI CC messages for changing the Attack/Release Times and Filter Cutoff/Resonance of the voices.