What else do I need?

I'm building this to do some slow wide drones mainly. And some mono basses, maybe a little bit sound design.
I also have a Korg SQ-1, and a Korg MS-20 Mini.
I want this to be all analogue. Will plan on a full digital system later.

1. Do I need more modulations to do drones? With this system, I'll have 3 VCLFOs(up to 5, If I count the VCOs), 3 envelopes.
2. Do I need Ringmod? Phaser?
3. I like the 9U cases from Doepfer. Should I go for the plywood one(a-100lc9, $460) or the metal one(a100p9, $675)?
4. Do you think a switching PSU is a better choice than the linear one that built in the Doepfer cases?

Any opinion is welcomed!
Thanks!

EDITED Dec 5th 2015, 17:59

I would add effects, but that's just me!

I would add effects, but that's just me!
-- Mrknobs

Yes! Planning a skiff for effects only.