From everything you've told us in this thread (power, space, desired bass response) I would suggest going with the Sundown Audio Z15
There's been a ton of testing by both Jacob (SA owner) and Bumpin Buick and just from an SPL standpoint I'm impressed with this little beast. Not to mention the testimonials of how it's also very musical. Now I have yet to actually hear one but from what people have been talking about it's pretty **** good, especially for the price point. Add to that the customer service and it's a closed case
Plus it looks cool....and that's what counts