Colton (and I) want to use Jessie (Debian 8) because it is the last working Debian version that supports powerpc and ppc64. Unfortunately, the repo at
http://ftp.ports.debian.org/debian-ports/ only has unreleased, unstable, and experimental. Nothing there that looks like it is usable for jessie.
Adrian's work on getting a "ports" version for Debian 10 is still a work-in-progress and not yet suitable for a "production" machine. There's a bunch of us helping with the effort, and we are hopeful we can get it going soon. Big kudos to Adrian for spearheading the effort!