Personally I'd lean more towards a distro. Yes, it's more work than a single piece of software, but this also means that there's something to do for everybody.

Taking the firewall as an example - I don't C, so (for the sake of the example let's assume it's written in C) I wouldn't have anything to do. I do however Perl, Python, SH and what have you. So if we're working on a distro, I could leave the C stuff to somebody who knows their stuff (looking at bottomy), and concentrate on what I do best. Unless of course we decide to write the whole damn thing in C, then I'm still sh*t out of luck.