you should also invest into illustrator and quark express. these are used for magazines/business cards. Afterall i think if you got photoshop, its just enough. To be a good graphics designer, you should have creativity
i think you might be better looking at indesign than quark express: quark is so **** expensive and afaik printing/publishing places are moving over to indesign. printers will have indesign anyway or be able to handle pdfs so i just wouldn't bother with quark.