sorry i'm late on this. but the copper coil add's to the freguency responce of the driver, it helps bring the low end out a little bit. and the flatwind coil aids in much more power handling. You will be very happy with your sub choice
i will but the install probably wont be the prettiest, this will be my first time building the enclosure have always used prefab in the past. i am going to be running it off of a hifonics 7506 for now untill i can through some more money into it and get more power. i still have to email fi and get some enclosure plans or designs