Consider upgrading your vCenter to 5.5, SSO is much simpler and easier to manage, and there is only one install, no more multisite install or external database to deal with. Or at least have SS0 and web client in 5.5 as they are backward compatible.
I highly recommend watching these two sessions from VMworld 2013
If you are deploying new vcenters go straight to 5.5 and start upgrading the others to 5.5 as well, it is far easier to get this now.