REX50 isn't a bad choice, actually. While it's not anywhere near being a state of the art reverb processor these days, as a "module" that's accessed through something like a SND/RTN it seems like a good fit within a modular patch. You get that lower bit-rate "dirt" with older FX units like this, and that's a really good additional character to add to a sound when you can tamper with it further.