Just run:
sudo su
layman -f -o https://raw.github.com/fr0stycl34r/gentoo-overlay-tox/master/repository.xml -a tox-overlay
layman -a qt
layman -S
emerge --sync
Note: See [AUTHORS] (https://github.com/fr0stycl34r/gentoo-overlay-tox/blob/master/AUTHORS) for people who created these Ebuilds.