I own both the RS-100 as well as an Acoustic Research AR SRC. IIRC, the remote for the Sansui didn't have a mute function, if that's any concern to you or not. Also, there was no separate power button so to turn off you have to unplug the unit. The AR SRC has both these features.
You might also look into a Chase RLC-1 or Pioneer RC-760, both come up frequently on the auction site. But the Chase has a loudness compensation feature built-in which some people don't like. I think that Akai made a remote volume unit but can't remember the model number offhand - probably fairly rare though.
One thing I'd recommend is that whatever you get, use the original remote and program it's features into a newer learning remote. No sense wearing the original one out. I've programmed the AR SRC functions into a Sony RM-VL600 with no problems.