Here is some more information on the test server and the commands you can use:
Test Server: Singularity - FAQ and Information
You could coordinate with him using Tranquility and then both of you switch to the test server. If you meet him in the same system you will see him in local. Also normal chat works in the test server, so you can start a conversation with him.
Most items are seeded for 100isk on the market for testing purposes. They are seeded on some NPC stations, but not on every single station - scroll through the market window and check other NPC stations in your region and you should find it, or try a neighboring region.
There is no fixed schedule. (well none that CCP has made known) They usually seem to mirror it once ever 3 or 4 months. However, the mirror also happens sooner and at other times - when they want to test new features, mass test, etc.