We actually have quite of a good rapport with our Debian packagers... so perhaps moving to Alioth could be a possibility, even though Octave itself is not a Debian package per se.
As for GNU, the problem is that we only have static sites there. It's not a huge problem, but it might be a good solution.
https://lists.debian.org/debian-devel-announce/2003/03/msg00...
"We'll approve ... free software/documentation where a Debian developer is heavily involved (part of the core team for example). The project request should ideally be done by a Debian developer."
Alternatively, can you get your webpage hosting onto gnu.org?