Buy 4 used speakers (I prefer pioneers)
Buy a decent used deck (Again pioneer)
Rewire to the new speakers.
Done.....
Craigslist is friend.
I also vote for new speakers They sound sooo much better
06 base open cone,2.5 inch dp into high-flow cat,window tint,drilled rotors.
97 GTP ubend delete,drilled and slotted rotors,de-badged,open cone,6k HID,All aftermarket speakers