You are making it more complicated than it realy is. Seperate voice coils are simply seen as extra drivers or subs by the amplifier. Wiring up a quad 4 ohm sub would be the same as 2 dual 4 ohm or 4 single 4 ohm subs. You will wire up the negatives of all four coils togeather and run them to the negative of the amp. Wire up all positives of the coils and take them to the positive of the amp. This places all the coils in parallel. Here is a very good link to JL's tutorial. It does a great job of breaking down the wiring and showing how to do it. You want to look at wiring 2 dual 4 ohm subs in parallel/parallel. You will see that four 4 ohm coils will yield a 1 ohm load.
http://mobile.jlaudio.com/support_pages.php?page_id=161
