Debian packaging of the q3c and pgsphere extensions

Hi,

I am posting to both lists since I am unsure where the best place is. I
am however not subscribed to any of them, so please keep in Cc for the
moment:

As a dependency of the Virtual Observatory "DACHS" package [1], which I
am planning to package, I need to have the "q3c" [2] and "pgsphere" [3]
packages in Debian. All packages already exist in a separate repository
[4]; the initial packaging was done by Florian Rothmaier.

However, I am very new to Postgresql extension packaging, and therefore
I would ask to get some useful hints here. Especially: Is there a Debian
policy for postgresql extensions that documents the preferred way for
packaging? A preferred git repository? Or is the Debian Science git
repository OK? Are extensions dependent on the postgresql version, and
if yes, how should I create the package to enable smooth transitions?
What are the preferred names for the packages?

I would be glad to get some initial startup here (maybe a simple
template or so)?

Best regards

Ole

[1] http://docs.g-vo.org/DaCHS/
[2] https://github.com/segasai/q3c
[3] http://pgsphere.github.io/download.html
[4] http://soft.g-vo.org/repo