Well, take note of the fact that you've overrun by 1 hp, but since that's with the Clouds and the Clouds is discontinued, that gives some more room. Now, if you also tossed the Erica module, that would open up a few more hp, enough to drop a Morphagene in...which is sort of Clouds-ish, but way more hands-on, control-wise. But then, there's another problem in that the 104 Moog case doesn't have the line-out that the Mother32 case itself does, so you're going to have to add an output module...which kills the Morphagene, space-wise. Hmmmmmm...
Ah! The SDS Reflex. 16 hp, all of the bells and whistles of the Clouds and more besides, and THAT will give you 4 hp for an output module, in stereo even. Maybe look at Happy Nerding's Isolator...transformer-isolated and balanced stereo outs with a ganged stereo level control. Nice...and a good combo with the Reflex. Should work just fine!