Definitely keep it in PM if you're going to press. You walk into a print shop with a Publisher file and the people look at you like "sure, whatever you say" and laugh when you leave. Then they wait until you get back to the office to tell you "we can't print this for you in this format. Can you give it to us as a PDF file?" and there goes quality right out the window.
I know that Quark Xpress comes with a converter for PM files, but don't know how well it works. If you can take the time to familiarize yourself with PM, you won't regret it. Adobe has given almost all their programs the same "feel" (PM, Photoshop, Premiere, Illustrator) and even added some cross-program features (Photoshop effects in PM). Try it out!