Can I hook up (4) 6x9's Pioneers, 450 watts (each) speakers down to 2 ohm.?

I'm looking to replace my high clearity Interfire amp (4ohm stable) on my boat, to use it in my system for my project El Camino. The Interfire amp is a true 1200 watt amp. No mark ups.This amp makes these x9's CLOWN EVERYONE at the lake.You can hear every instrument in any song. Should I replace it with a 2ohm or stay with a 4ohm amp. They say the dumbest question gets the smartest response. Help me out dog. I'm tired of spending thousands at the shop, for something I can do.