Thanks for contacting Linode. We are unable to swap or add additional IP addresses in this datacenter since we have opened our new Tokyo 2 datacenter, but we would be happy to explain your options.
We suggest cloning your current Linode into a new Linode in our new Tokyo 2 datacenter. The cloning process allows you to troubleshoot any issues with migrating to the KVM platform if they should arise with minimal downtime, as your production machine is still up and running in its original location. You will also have more time to update DNS records since you will be issued an IP with your new Linode in Tokyo 2.