System Rescue used to be Gentoo based and then switched to Arch. You can install both Arch and Gentoo with SR and obviously you can install Arch with a Gentoo

System Rescue used to be Gentoo based and then switched to Arch. You can install both Arch and Gentoo with SR and obviously you can install Arch with a Gentoo install CD and vice versa. SR also has some rather handy SAM database editing facilities. Mount Windows at /mnt and then enable and reset the Administrator password. Jolly handy for getting super duper user access on a Windows box. Its been a while since I installed Gentoo but you can probably quite easily add more stuff to your Gentoo install CD. I don't know if Gentoo have added a script to do all the bind mounts but "arch-chroot /bin/bash" is very convenient. I used to forget about /sys.