The links nothing more than an ad from the dude who sells those units on ebay. I bought one. Dubious quality.
Anyway, getting 2 to work is trivial. It sounds like you should try to get 1 working first and expand from there... If you already have 1 working, then you should no try to understand why and how it works. Then adding a 2nd or 3rd should be an exercise in utter-obviousness.
And finally, you'll probably get more sensible replies if you actually try it out and then post with specific questions referring to your current implementation and the problem/s it exhibits.
G.