Thats the Ruffstuff setup installed. No E-brake with the chevy calipers, you can do a caddy caliper setup, but they're expensive and apparently are a royal pain to keep adjusted.

I'm pretty sure to keep the 2wd style output on that ZF you have you are going to have to keep that brake on there. And if you go with pretty much any aftermarket rear disc setup, it will be your best bet for a parking brake.