The Red Lion part # for the modular controller is CSMSTRSX. For a few hundred less, you can get their G303 screen which will do the same thing, but isn't DIN-rail mountable. You could probably do something 'custom', though
You have a couple of options to get the Automation Direct PLC back to your RSView PC. And the easiest/best way will depend on where you decide to put the Red Lion unit. If you put it close to the PLCDirect PLC, you could just use the RS232 'DirectNet' protocol, as long as your drop isn't much over 20 ft. If you need to mount the Red Lion unit further away, then you could use a serial-to-ethernet, or serial-to-fiber converter, but you would need one on both ends. This would cost about $400, and you would still have to run CAT5 or fiber. The quickest/easiest way is to use Banner's Data Radios, which would send the DirectNet protocol wirelessly for up to 3 miles line-of-sight. This way there would be no cable/conduit to run, but the (2) radios would cost around $1000 total. You would probably save that easily in labor/wiring costs, though.