Best musical sub around $1k


Looking for some advices on sub.

I am deciding between Sonus Faber Cremona Auditor + sub or go full range and get Cremona. If I were to go with Auditor + sub, I will need to keep the cost down for my decision to make sense, hence the $1k budget. I like the stregth of mini-monitor - imaging, better coherence (2-way vs. 3-way), and easier placement. But Auditor needs to play loud to sound full range and I don't have that option most of the time due to my power amp (BAT VK-75SE) and small kids. So getting the Auditor will require a sub for my need.

So what sub will you recommend? I had a REL Stadium III before, but price is out of my range right now. Cremona sub is also too expensive. Are the smaller REL as good as Stadium III or I am better off getting an older Stadium (II ?)

Or to complicate the issue further, get a floor standing Cremona instead?
semi
Vandersteen 2WQ new at $1400, used about $800.00. But you do have to spring for the fixed filters; try and find aftermarket which are made with higher quality parts than OEM. 3, 8" w40 oz magnets. 300 w onboard amp.
I have a chance to buy a Storm III for a little over $1k, but heard Stadium III is a big step above and I am debating if I should save up more to move to a Stadium instead. Will Stadium III be worth the extra $1k or will I be equally happy with the subs recommended above?

I know Stadium is a fine sub, but at $2k+ used, total price with monitor speakers is pushing very close to floor standing speakers. To me, sub is an accessory that never works well 100% of the time. Sub + monitor will never rival floor standing speakers in integration or coherence, so spending this much money on an accessory is really a tough sell to me.

Did I just answer my own question?
I am also looking into a new sub. The SVS pb2+ is making a big splash right now. I would like to know how it is musical.

Tim
If you go with Rel I would recommend the Strata before the Storm, but the Stadium is very nice :)