I'm not sure what slide mechanism is in the '09s, on an '08 or older model, the slide mechanism is attached to the bottom of the board that the goucho sofa sits on. Any modification to that area would require a complete re-engineering of the slide mechanism.
We have some friends that have a '10 244RBS that has the slide mechanism down both sidewalls, but, that seems to be over-engineered for the smaller slide of the 210WBS. Not sure what slide mechanism is in the newer 210WBS models, but, if it is still under the couch mounting board, you are severely limited in what can be done to that area... The pictures of the '11 models look like they are using the same sidewall slide mechanism as the 244RBS (full to floor slide) and that sofa looks like it could be easily replaced as you want. You'll need to investigate as to what type of slide mechanism your '09 has...