I could give you access to test installations to Liferay, GateIn + eXo WCMS and OpenCMS. I'm a startup ind Germany and I will sell this Solutions as Saas or as an Consultant for your own Cloud.
For a simple Typo3 replacement I would currently prefer OpenCMS. If you need more then Liferay and as a option Hippo HST. Even more hungry then GateIn/eXo Portal. OpenCMS and Liferay are more friendly for the users. GateIn/eXo Portal has more flexibility for your company. The design is full modularized.
All three solutions could be conncted to LDAP. See here an example for GateIn http://community.jboss.org/wiki/GateInWithLDAPAsADefaultUserAndGroupStore