Multi Tennancy Setup

We currently have an HCO setup which just monitors one client.  I have been asked to look into the feasability of converting this into a Multi Tennant setup.  What do you lot think I should do.

1.  Just add the new clients stuff to the existing setup and create custom views, custom properties and account limitations to segregate what each client sees.  APEs on each client site reporting back into the centre.

2.  Create multiple instances of HCO, one for each client, and use EOC to manage it.  

Not done this before so just looking to start a discussion.  As usual cost will be a factor.

Thanks in advance.