Minimal but useful Linux userland, COW filesystems footprint

Hi, I want to try Linux Containers (LVC 1.0 is out) and BTRFS (in a way I use FreeBSD and Jails and ZFS). I want to use filesystem cloning (at the moment under FreeBSD "cd /usr/src; make buildworld; make distribution; zfs snapshot; zfs clone") I also want to have a small but useful userland.. I am thinking of a "minimalist" Debian installation but other ideas are welcome too. Do you have good advice to achieve this? (TW: I am not a huge Busybox fan, the tools always seem to miss the one option I want to use.. so, no scaled down tools, just a good set of "standard tools") I do not know about the memory footstep and minimal requirements of BTRFS and ZFS under Linux, comments and advice is welcome as well. Thanks Peter