I'm not a FreeBSD user, but as far as I know, Gentoo's portage is pretty similar, and I'm familiar with it. I think that would be overengineering at the moment.
About Quicklisp: it seems interesting. It seems pretty similar, but I don't know it in detail.
The tools I'm building are similar to Rake (ruby) / NPM (node.js) / Yeoman
What I'm doing is a set of curated libraries growing organically. It's everything pretty simple, though. It's better to have something simple that works, and build upon that. Just like Gambit does, but for the application developer who wants to start from something and still have all the flexibility Gambit provides.
I'll create better documentation during the next days, so the most important pieces are well documented, and can be improved on top of what is already done. There is a lot to be done =)