Thanks for the responses guys. I am learning more and more each day.
Just a quick follow-up question: if I were to build a frankensub, and assuming I were able to source both the mbw sub (not the 1680) with lug holes or the twn best sub also with lug holes, which one would you choose (and why), MBW or Twn Best? Also note that I don't really have a lot of money to spend on mods, but I am willing to do most of the mods myself. The key I guess is which of these reps can take either gen or aftermarket parts with little or no mods. Thanks again...