Universal Remote Control (maker of the One-For-All universal remotes) makes a
thing called URC 3000 (about $30.00). It is an IR to X10 box. The URC 4050
remote control is pre-programmed to control the box and it's IR commands
can be learned by the Marantz and maybe the Sony. I've done it with the Marantz.
The URC 3000 provides the ability to control 16 X10 codes (in one house code)for
on, off, all on, all off, bright, dim. In addition if you have the IBM home
director, you can send one IR command to the URC 3000, it sends one X10 ON
command over the power lines, the IBM home director can be programmed to detect
that one command and send out a whole sequence of X10 commands so you can set a
"scene" with one button press on your IR remote.