Im just wondering how you guys set this up?

For example I have two products that use SQL, for this I'll just say Sophos Server and APP-V

Now what would you do now
1)
Sophos with its own virtual server and SQL installed locally on that virtual server.

APP-V with its own virtual server and SQL installed locally on that virtual server.

2)
Sophos with its own virtual server and SQL installed on another virtual server just for this database ie that server would be called SQL-Sophos.

APP-V with its own virtual server and SQL installed on another virtual server just for this database ie that server would be called SQL-APP-V

3)
Sophos with its own virtual server and SQL installed on another virtual server that uses 1 instance for multipull databases (so all SQL databases in the network are all on this server in one instance)

APP-V with its own virtual server and SQL installed on another virtual server that uses 1 instance for multipull databases (so all SQL databases in the network are all on this server in one instance)