If your going to assemble your projects onto one computer, why not one of your existing ones? I'd have one version control repository (cvs, subversion or to taste) per tarball and use tags to record the history of parts explosions including source versions that went into every release. That way I can write Perl scripts against my repository that can help me quickly track down a culprit change even if for example a bug is reported two releases down the road from its cause.