poohboi ,
thats a lot of money.you can get an awesome system for that.
you have to know your needs - do you want soundquality or SPL(loudness)
do you want mp3 or just a CD receiver or both.
ill recommend some brands and it is up to you to decide.
also think about the install to run you 1/3 of the budget if you cant install it yourself.

headunit - nakamichi CD45z sor awesome SQ ($300)
or other alpine decks ($300-$350)

component sets - rainbow pro,focals ,image dynamics chameleon)

amps for components - arc audio

subs - IDmax , ADS , IDQ ,

sub amp - zapco , arc audio ,