Multi Site Highly Available

I am trying to ascertain if this is at all possible.

3 datacentres

3 set of users

Highly available RDSH/VDI sessions

Ability to cope with a single datacentre failure 

Seamless for users and administrators.

2012 brokers web access and gateways.

Hardware load balancers are an option - kemp loadmasters and geo loadmasters.

Windows 7, wes7, and above clients - thin or repurposed.

I appreciate that's a broad brush picture but there's very little info that I can find on this type of deployment with Just MS products (load balancers aside)

Thanks