question on intercoms for my new homebuilt

Over the last 4 years I've built a Pietenpol Aircamper, had it licenced last
fall, and have flown off the 25 hours. Now it's time to put in an intercom
for the front hole. I have two David Clark headsets already, and am running
an A-65 with unshielded ignition.
All the intercoms in the ads show a picture, but seem to be a single unit
that mounts to a bulkhead that both can reach. Mine has two cockpits that
are aways apart. What provisions do these intercoms have for the extra
distance???
And will the unshielding be a problem???
--
walt evans
NX140DL