My 2012 C5 has a matching Inder sidecar attached by the dealer. It does not interfere with the kick starter. I have used my kick start a few times without interference - just my poor coordination and lack of practice on the kick start.
For the older Bullets, I believe the Cozy sidecars are recommended - slightly lighter weight. The Inder are almost identical to the Cozy, but seem a little more solid and have a brake option on the sidecar.
There are other vintage styled sidecars available from US makers as well. Find the lightest you can as the bike does not have much spare power for the heavier ones.