From my (admittedly limited) experience, yes, you will want to eventually get a Mac of our own for development. I'm not sure if there is a way to create .dmg pa

From my (admittedly limited) experience, yes, you will want to eventually get a Mac of our own for development. I'm not sure if there is a way to create .dmg packages otherwise, but you will definitely want to be able to take advantage of the Cocoa libraries if you're doing GUI apps. The most common recommendation I hear for strictly cross-platform development is to get a Mac Mini; it can handle pretty much any "normal" development tasks you'd need it for.