I have cluster of ASA 5512-x and I my customer want to filter websites based on category  , and before I order the required licenses and subscriptions I have few questions : 

1- did I need both WSE and AVS to be enabled to filter out sites like facebook ? 

2- I have to buy two subsception for both boxes ? my cluster is active passive ?

3-my firewalls has IPS enabled , did this in any way conflict with WSE and AVS?  

4- I have classic IPS on my firewalls how easy to upgrade it to firepower 

actually I search on internet but did not get clear answers , so please if some one can clarify my doubts