Considering Gentoo

I have an old iMac that I am planning to install some flavor of Linux on and while I was looking at various distros it occurred to me that it might be a good exercise to install Gentoo on it. Other than a separate machine for documentation and downloading the necessary packages, what else should I have set up to try this? Has anyone installed Gentoo on a Mac before? If so, what concerns are there related to things like Apple’s implementation of EFI?