I would get either a Greddy or Apexi exhaust. I haven't heard much about the Magnaflow but they look to be of high quality construction.
You may have to worry about rust too, so Greddy's exhausts come fully stainless steel. It won't eliminate rusting but it will retard it better than Apexi's mild steel.
Personally, I would go with any Greddy exhaust since they have a great tone to them, they are high quality stainless steel throughout, and are decently priced. Just my $.02, though.