dont do it...
that drumbox has got no MIDI (that midiport on it is only dinsync for syncing) and the synth is a very basic DCO thing....if you really need that specific Korg Poly61 sound maybe, but otherwise get something more modern hehe
Vintage isnt all that good as the hype tells, it sounds okay ofc, but handling/progging/voice counts etc are so mediocre on those old things... (not to mention you wont have fresh keys and knobs, but sticky, skippy and just not new feel to it)
And the real good vintage synths arent affordable anyways nowadys...(like beginning from 2000 orso)
The rest is easily replaceable by modern stuff...really 
Perhaps looks at at BLofeld, DSI Tetra or stuff like that..just a suggestion.
Those cheap DCo synths are nice as a complementation in a large studio, where there are more workhorses around, but as the only or 2nd synth or so , I wouldnt advise it.
EDIT:
And yeah: its way overpriced