For all the high-end sim racing cockpits out Dark And Darker Gold there, including the Playseat Trophy Logitech G Edition I'm also testing, it turns out a foldable racing wheel stand such as this one from Monoprice was all I actually needed.
It's in no way as snazzy or comfortable over long periods as the Playseat, which I'm sitting in as I type this, and it won't place you into a proper racing position, either. But it's pretty affordable, fits my wheel comfortably, and conveniently folds down to a storable size.
The most important thing is that the Dark Matter GT stays in place when I slam on the brake pedal. I've screwed the T3PM pedal set from the Thrustmaster T248 to the base and now it's firmly locked in no matter how much I stab at it.
Honestly, it's brought back a lot of joy in sim racing for me, and I didn't entirely grasp how much pedals that move about all over the place under braking affected my desire to get my racing wheel out until now.
As for the Dark Matter GT, it's a fairly stripped back concept. There's no chair component, like you would see on many cockpits, so you'll have to provide your own (may I recommend one without wheels). It's simply a foldable frame for the wheel base, pedals, and a shifter, if you have one.
Setup was quick and painless. The core frame comes mostly assembled, and it's only the hinge covers and a few smaller pieces you need to add on yourself. No part of the job is particularly fiddly, and I had the whole thing put Dark And Darker Gold Coins together in 15 minutes.
The Wall