Actually, that's one of the things I love about dynamic cloth; the texture maps can be flat to the real fabric. Check out Serge's stuff to see how he uses this. Most Mac-made Poser stuff is usable across platform. Simply put, playing in a mostly PC world has made us experts in translating in and out of cross-platform file formats. Unless there's a .sit extension (and even then, often), you should be able to use it just fine.