I need a Digital Audio Converter/Swithcher Box which will accept at least one optical input and one coax input and has a coax output. Of course, it must be able to convert the optical input to a coax output and switch (automatically?)between the two inputs. Finally, my budget is $100 for this box. Alternatively, I could also buy a simple optical to coax converter and run another coax cable, but I'd prefer to simply use the one I already have in place. Anyone know who sells a box like this? Thanks!