scp and "dpkg -i" are readily available, but it's really not that much work to setup a repository (aptly, reprepro, apt-ftparchive etc.)

I know I'd personally chose maintaining the system packages and where possible put extraneous language dependencies in packages too (fpm comes in handy as it can deal with a variety of packages, gem, npm etc). It makes life a lot simpler when it comes to administering a bunch of systems and trying to keep things consistent.