Recommendations for Identity Solution in Red Hat environment.

My group continues to research solutions that will provide cost-savings, improve stability, ease-of-management, etc... Fortunately - we embrace Red Hat as the strategic platform.  

We have Red Hat Enterprise Storage, Red Hat Network Satellite, RH Cluster and are considering Red Hat Storage and CloudForms.

Currently we are researching the optimal solution for Identity Management.  Active Directory will ultimately be "the source".  

My question(s) are:

• is Identity Management (formerly IPA) sufficive for our goals?  Or, should we put more consideration behind Red Hat Directory Services?
• Are there any "future gotcha's" that we need to specifically consider in our selection?
• Do you feel that if we make a decision at this point that a migration to another strategy would be considerably overwhelming? (i.e. if we chose IdM now, and decide to migrate to RHDS later)

At this point, I personally feel that IdM would be quite sufficient as we mostly need to only provide a password conduit back to AD and possibly automount.  However, I am worried that we may decide to implement something in the coming year that might cause some regret.

Thanks in advance!