Thinking of getting/building another subwoofer, Supercube 1 Earthquake, Dayton

[Ratamahatta 437]

There are two subs on E-bay I was considering A Definitive Technology supercube 1, the add says its new but damaged in shipping, Looks like it can be repaired fairly simple.  I have heard them before and was fairly impressed but it has been a while. It was 450 with shipping included http://www.ebay.com/itm/261654981261?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

2nd is an earthquake, I have never heard one of these but hear good things.   http://www.ebay.com/itm/111477391951?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

and last is a Dayton 12" Ultimax with the pre cut enclosure from parts express  http://www.parts-express.com/dayton-audio-12-ultimax-subwoofer-and-cabinet-package--300-7096  I am going to use the Yung 500 watt amp but cannot decide on the one with or without boost.  Right now this is the direction I am heading.   Thanks in advance. 

[Gene C 1,753]

Here's a recommendation for the $500.00 neighborhood. Martin Logan Dynamo 1000 on eBay would offer him $525.00 and see if he takes it. Paid $700 new each for both of mine on eBay when they retail for 1K.