EBS 12.2 does indeed have significant changes in both the AppsTier and the DbTier, and the next version of the Delphix Engine (v4.2), coming out in a few weeks, is equipped to handle them. The new Engine handles R11.5, R12.1, and R12.2 of EBS.
The free-trial version of Landshark is purposely built to contain only free software, so they only contain Oracle XE and PostgreSQL on CentOS.
There are internal-only Landshark versions that have Windows, SQL Server, and Oracle EE onboard for testing purposes, but (to my knowledge) there are no Landshark versions with the pre-release version of v4.2 of the Delphix Engine just yet.
Soon though... :-)