Affordable subwoofer for music cont'd

So a while back I posted a thread asking for opinions for a sub that would go well with audio as opposed to home theater. I laid out my system, NAD w/ MA Silver 3i speakers, and that I've spend well under $1000 on it all so far. Many people suggested that the only suitable sub for music would be a $1500+ sub; well out of my price range.
So, I did some thinking, and realized that if I either limited the cone mass/size, or had a sealed enclosure, I would have a tighter sounding, more musical subwoofer.

In light of these simple observations, I've been looking at some used subs on here and ebaY. So far I've found the following, all within my price range.

My question is this: assuming the same price on all of these, which one would you choose?
Paradigm PDR-8
Defintive Technology ProSub 80
M&K K9

I am asking for this advice because I have no way of auditioning any of these subs. The Paradigm seems like a decent affordable sub that is a compromise between the DefTech and the M&K. The DefTech has really low bass response (21Hz) and a decent amount of power, but I'm not sure how musical it is. The M&K only is rated down to 35Hz (I think) and has only 75W, but is probably really musical. Any comments are appreciated!