C/++, SDL and possibly GL|ES 1/2 is probably a good starting point. While it's probably doable to write games for pandora/pyra with mono, performance may be lacking, especially on the pandora.
Don't worry about packaging for now, when you get it working as it is, getting it to run from a package will be ≈ like running it from the build directory. Just keep your dependencies in check and you'll be fine.