ADFS requirements for O365 SSO

Hi,

I have < 100 users in the organization. I do have users connecting via mobile devices to access email on O365. Please let me know if this is an acceptable setup or if there could be improvements to reduce the overhead.

1 ADFS on the internal network (no farm/NLB)

1 ADFS Proxy on the perimeter network (no farm/NLB)

1 standard Secure Sockets Layer (SSL) certificate with the subject   adfs01.domain.com

1 public IP address to resolve the adfs01.domain.com externally

1 self signed X.509 certificate for the internal FS

Also, The following article recommends a server farm/NLB for both the internal and the proxy FS. I need to know if this is actually MANDATORY or not.

http://technet.microsoft.com/en-us/library/jj151794.aspx

Please let me know if I have missed anything or if I have stated anything here incorrectly. Thank you for your help!

Regards,

Thilina