As to the rest of the speakers, It's hard to get good speakers in the dash (although you can buy / make adapters) - it may sound better to go with some sound pods.
Stock head unit, Upgraded 6.5 rear Sony Xplod 4way and 5.25 up front Sony Xplod 4-way off teh rollbar plus Kenwood KSC-SW1 under the seat. There is a newer model now KSC-SW10