Wilwood setup is nice. I got to check it out at PRI

https://www.instagram.com/p/B6Ssqi2Jc2l/

Thought I'd share my version...

Well done sir!

Very interesting

Is that the e-stopp setup?

Niiiiiiiice!!

It is the e-stopp actuator with my version of a cable connecting bracket.

After poking around at some OEM electric parking brake solutions it looks like some are using Tesla rear calipers for parking brakes.
Calipers can be found for $50-$100/pair on ebay...
https://www.ebay.com/itm/Tesla-Model...EAAOSwnlRewe4a
A company sells a controller for them with a few actuation options...
https://www.pantera-electronics.com/epbcontroller.htm
You're on your own for brackets in most cases.

The calipers operate similar to a reverse polarity power window, and I had a spare window controller laying around so I'm going to try using that and see if it works. 2-way momentary switch, 1 way for engage and the other to disengage.
https://www.amazon.com/Directed-Elec.../dp/B00H4N1Y2O

I like the e-stopp idea but if cables can be eliminated completely that would be ideal.

https://www.pantera-electronics.com/...iles/86229.jpg

Prolly can be done with regular Bosch 5-pin relays

You lose out on the load sensing aspect, but 2 relays would certainly work from a pure function standpoint.