CRM 2011 with IFD DR/High Availability

Hey,

i have a working environment configured with IFD, the ADFS server is located on the CRM server and i have a separate SQL server.

i address the CRM via TMG all works fine.

Now i want to make it high availability so if the SQLor the CRM srevers "fell" it will still works.

the TMG is configured mostly by this guide:

http://dynamics-crm2011.blogspot.co.il/2012/03/how-to-configure-crm-2011-for-ifd-and.html.

what is the best practice for this to happen ??