well im at the point where iwouldnt mind spending some cash on an amp/sub

keep in mind im driving a prelude(not a big trunk), so id like some trunk space efficiency

i probably listen to rap the most-i want it to hit hard, but im not buying them to give people in nearby houses and streets an idea of what kind of music i like.

im trying to decide what brands to look for, and what size to get. ive been thinking 2 10's or maybe a 12. Im not sure how they compare, so any advice would be great.

i saw a few infinity 10s on crutchfield, the infinity reference 1040w
or perhaps the infinity kappa perfect 10.1
besides the wattage im not sure what would cause such a price difference--perhaps material of the cone?
those were just a thought any brands or size recommendations would be great.
id hope to keep it under 500, btw

thanks for the help

mike