under live-build-config....but if you did somethink wrong THERE is no iso....here is litle help for you ...--->here is what you have to do: to create a iso for kali linux 64 bit kde:
apt-get update
apt-get install git live-build cdebootstrap kali-archive-keyring
git clone git://git.kali.org/live-build-config.git
gedit config/package-lists/kali.list.chroot
and delete everything after:
# Graphical desktops depending on the architecture
#
# You can replace all the remaining lines with a list of the
# packages required to install your preferred graphical desktop
# or you can just comment everything except the packages of your
# preferred desktop.
and add instead replace it with
kali-defaults
kali-root-login
desktop-base
kde-plasma-desktop
kde-full
kdm
wicd-kde
then
cd live-build-config
lb config --architecture amd64
sudo lb build
thk you and good luck bro!!!