Vortex Sound Research

I’m just starting out. I have a 9U 128hp rack. Before my case was finished I ordered a DivKid ochd and a Bubblesound uLFO. That’s it.

Ultimately I want to make wall of sound, shoegaze, trip hop, ambient beats, and just general “cool fucking sounds” to use as the backbone or behind other instruments.

I’m looking for a mixer, what do I need to look for in a mixer? Channels, mono/stereo, headphone out? There were a couple other things on Doudoroffs that I didn’t understand.

A little help please