Hehe, no idea if you do the stage 3 ISO, but if you do stage one be prepared for it to take at least 4 hours to do the initial (minimal) install and then add compiling time for every program you want there after
(by minimal I mean CLI only and basic system utils)
Gentoo basicly does what Linux From Scratch does, just slightly more automated.
(ie instead of manually building bash, bin-utils, then glibc, then rebuilding them all manually it is scripted to do it, but it takes the same amount of time)
This is from stage 1 though.
Stage 3 takes about 20 minutes to install, but leaves you with a minimal install again i believe.
Jkrohn