Go for Pioneer...

Install a Pioneer Subwoofer(1000W) with a Pioneer mono amp (800W will do) & 5 way oval speakerz @ rear n 2 door speaker for the front.... u can keep tweeterz too...

for the head unit..... well it depends on ur budget..

if u install...dvd playerz..it will b awesome... but..its kinda xpensive....

i bet ..with these.... ur car will rock....

cheerz!