ive got...
2 x kenwood 130 watt 4 inch in the front doors,
2 x sony xplod 250 watt 6 inch component speakers in the back panels,
2 x 12 inch subwoofers in a ported box in the boot,
a 1000 watt amplifier to run the sub woofers
and an 800 watt amplifier to run the 4 speakers in the doors and back panels....
and a very ill fitting pioneer bluetooth head unit in the pitifully small space that landrover put the stereo!!!
the mirrors vibrate with the bass when i crank it up!!! lol
and all together it cost me more than i paid for the truck!! lol
so what im trying to say is you dont have to replace like for like.... just as long as they fit!!