Help picking a sub

Hello all,

I've been in the process of upgrade the sound system in my 330ci cabrio. So far I've replaced all the speakers with the BSW stage 1 kit and am pretty satisfied.

Next up is the Sub. I've looked at the following options.

BSW Stealth Sub

Kicker Solo Barric 8" using this enclosure

http://fgseonline.com/shop/bmw-coupe...sub-enclosure/

Or a 12" down firing sealed box with a 300 watt JL12"

I'm looking for something clean, punchy and very tight.

The Solo Barric is probably the most punchy, but its only 8". Will that be enough for thick low reaching bass? Or will the sealer 12" deliver a deeper sound since its significantly larger? The downside of course is that I'll lose a good chunk of trunk space, which I would like to avoid.


Finally, can anyone say anything good about the BSW kit? Is it worth the $700? It only comes with a 230 watt amp, so its gotta be the least punch of the three right?

Can anyone share some insight on this?

Thanks!