The IPCP 505 should be perfect for want you want as it has way more serial ports than you need. It also gives you IR and relay control as well.

This unit has Phoenix connectors on the back. The photos on the Extron web site shows the back of the unit with the plugs removed from the connectors. Your wires hook up to those plugs just by stripping the insulation, inserting the wire under the terminal on the plug, and tightening the screw with a tiny screwdriver. The you just plug the plug into the back of the IPCP 505 into the appropriate connector. Some of the RS-232 Com ports (COM 7 and 8) on the IPCP 505 have additional connections (RTS/CTS) which may or may not be required for any of your connected equipment. Also, the additional ports which are both Serial and/or IR only send out a serial command. Because you're mainly just telling your other pieces of equipment what to do this should be all you need. However, Com 1 -8 has transmit and receive so you would be able to get a status report from the attached equipment.

You could buy some 10 ft serial cables, cut them in half, plug one side into the 9-pin connector on one product and then strip the other end to attach to the IPCP 505. That way you'd get two serial connections from one cable.

I hope this helps! Hopefully you have the manual for the IPCP 505. You may need to search through the paperwork of all of your devices, or do an online search of RS-232 Serial pin-outs. The standard serial port connector has 9 pins but as few as two of them can be used for sending out commands. You need to find out which of the nine wires in the serial cable connect to the 2, 3, or 4 terminals on the Phoenix connectors.

Be careful when buying serial cables - make sure both ends fit into the jacks on your equipment (male or female). Also, some cables have some wire pairs flipped on one side (null modem cable vs. standard cable). To be certain you may need to use a VOM or continuity tester. Also, make sure all of the COM settings (Baud rates, etc) match at both ends or you'll have problems communicating. Sometimes you can run into problems getting serial communications to function properly, but once you do it will be rock-solid.