Installation instructions are on the official wiki. Alternatively, I can do the installation if given access to a remote terminal.
Basically I proposed a method where we hang kernels, images, and ISOs off of master-releases.gentoo.org via rsync, and we can then push custom kernels (like a BSD kernel) and custom ISOs (so you can boot into something) without filing tickets to the OSL all the time. That is a blocker before we can move forward here; but it should be technically possible to do a gentoo/kfreebsd VM.
reopen if still needed