You're mixing apples and oranges.

The Sony RM-X4S and the interface on the tuner are WIRED units that use a resistor network. The SWI-X and sony IR remotes use INFRARED and will not interface with the tuner module at all.

By asking if the RM-X4S is the same an an IR remote, you are stating a non-sequitur. And by asking if you want to wire the SWI-X to the tuner, you are also stating a non-sequitur.

For more details on wired and wireless interfaces, please see this FAQ entry.