I was wondering if you had two subwoofers and boxes that were identical except for that one box has a port and the other does not, if the one with the port can handle as much power as the one with out the port, I would think that the one with the port would run the risk of being blown quicker at lower power levels. The other question is are there woofers just made specificly for a port.
No, not with low power levels. With higher power levels, ported boxes can't control a sub's excursion as well as a sealed box because of the internal pressure. When you hear that a certain 300WRMS sub is underrated because they're pushing "more power they the sub take" in a sealed box application, a lot of that reason is because the company has to underrate it to safely be used in all kinds of enclosures, such as ported, bandpass, and free air. There are subs made for ported boxes, yes. Many SPL subs work better in ported applications.