the oc8 was something they did in the earlier models, I believe it is hard to get a nice interface for that..
you are right, the dcb interface will not help here..
the se is ok and groove electronics one seems no longer available..
so, finally you might go for the kenton,
hmm.. I do not remember if SE had one kit that can be fit into the Jps case, so you do not need external boxes..
it's such a long time when the groove electronics thing was talked often..
there are 2 people I'd ask:
1) kevin lightner - www.synthfool.com
2) Achim Lenzgen - http://sequencer.de/synth/index.php/Synthesizer_Repair Reparatur-Service Liste
I am sure they know the best solutions for TODAYs http://www.sequencer.de/roland/roland_jupiter_promars.html Jupiter s
maybe interesting ,too:
from Rudi Linhards site.. thats the groove elec. kit..
possibly you can get one, the address is in the pdf..
nice SOS article:
http://www.soundonsound.com/sos/feb98/a ... piter.html