I have a setup similar below. Everything works, however, equipments are all in one place close to my HDTV set as of the moment. I am putting all the equipments in the basement together. Wiring is there, I have 4 coax RG6 quad cables and two Cat5e going from my head end location to my HDTV set in the family room. If you look at the Cat5e cables, it's free. I haven't used it for anything.
Here is my situation. I'm looking for the cheapest but reliable way of sending my remote control signal to the basement when I am in the family room so I can control my Comcast set top box or other equipments. I remember last year, there is an IR device that will allow me to do it but I couldn't remember it anymore. Once I found out what device that is, I should also be able to control my AutoPatch via computer using LIRC.
You should be able to do this for less than $100 or thereabouts. The Hot Link solution used by sunnyvali and sixdoubleo as well as the the Buffalo solution used by Haslip seem to fit your requirement (extremely reliable). There is also a specific, but slightly more costly solution from Hot Link not used in any of these examples that is intended for longer distances using cat5 or cat6 wire and standard RJ45 connectors to cover distances up to 200 feet.
Ok, I will look into it as well. I saw haslips solution and I like it. I have many devices as opposed to the drawing I have above. My confusion now is about connectivity if I wanted to control the devices in the basement from 2 or more rooms.