License Cisco ESA in Cluster Configuration

Question

Guys,
Do you have any idea about license Cisco ESA in Cluster Configuration
> If i have two appliance in cluster configuration and i have 1000 user, which option for license i must buy ?
1. Just one license for two appliance (which in cluster configuration) with 1000 user capacity
2. Two license with 500 user capacity for each appliance, appliance 1 with 500 user capacity license appliance 2 500  user capacity license
3. Other license.
BR

Answer 1

You only need to buy 1000 user licenses for which ever options or packages you buy. The only option that is not based on the number of users is if you want a Cisco Content Security Management Appliance or SMA for centralized reporting and quarantine. 
Another good thing to note, is that if you have a virtual environment the hardware appliances are no longer required, and are not nearly as expensive as they were in the past. So depending on your requirements you may be off the ground pretty quick.
Also make sure to get all your features bundled. I would at least get AMP, Sophos A/V, DLP, and Encryption. This also means you can transfer and copy your license to as many appliances (Physical or Virtual) you need to support your environment.