I've read multiple posts of people who are using the sony stalk controller with their Empeg, and I started to get interested because I want to use the buttons on the Empeg unit itself as little as possible. I believe those would be the first to go when it comes to wear & tear.

The sonicblue website makes mention of two types, the RM2XS and the RM4XS. I can't find any info on them on the Sony site. What is the difference between them? Which one works best?

Also, will I need to install the tuner module to be able to use those remotes? I have such a module, no problem, but I have no need to install it yet : my empeg is connected via my Pioneer headunit, which has a tuner. I merely purchased the tuner module for future upgrading (read : another car). i don't want to install it unless I really have to. It makes no sense to have two tuners in your car.
Is there a way to make those stalk controllers work with the empeg unit without having to install the tuner module?