Ur looking at almost 2 grand if not more for subs and amps for ur subs alone, that doesnt include ur door speakers the amp/amps for that, all ur wires, and ur alternators ur gonna need at least 2 of those for that power ur planning on having/wanting looking at another 900 for that. What exactly is ur budget, cause if its not a big budget ur not gonna get a 5,000 watt system. 18 inch AQ HDC3's cost around 375 a piece as a refrence point. and ur gonna need sound deadner unless u want it to be a rattle trap, so thers more $$$.
Just to let u know i have over a grand in my new setup for this spring, i already had the sub , sub and highs amp, i had to get an alternator, all the wiring, the highs, sound deadner (a grand right there) and other misc. stuff.