??
that's not true. how do you come to that conclusion?

you can install any debian based software package, including of course development packages.
they may not be in the default repositories, but as a developer one should be able to edit the apt.sources list *g*

@chris
i'd suggest ubuntu, it currently has the broadest support and is beginner-friendly, while still a good choice for pros/developers/etc. it grows with your knowledge

regarding Gnome vs KDE:
it basically really is just a matter of taste. you're not even limited to specific software suites for either of those two. KOffice f.ex. will run under Gnome without problem. It will need additional KDE-libraries, but those are taken care of by package dependencies at installation time. You will of course need a little more space for the additional libraries.