Hey Donut......... I'm looking for the same upgrade .
Let me know how you make out.
after much research, I've decided to try the PBR300x4
contacted a guy on h-d forums who has and makes a mounting bracket for that amp. If not I'll experiment
b. technology, weight, size
although it's a 4 channel out, and not bridgeable due to the nature of the switching algorithm I'd assume, I'm strongly considering adding vented lower fairings with speaker pods to add the other two channels. that's spending $500-700 to accommodate a $200 upgrade.
so, for the money, maybe just try it running stereo at first, already have the power leads, fuse and connectors, might end up running the 10 gauge power lead over the tank under the console inside a plastic sheath. didn't have much luck fishing the cable channel thru the tank. having a fixed fairing makes cabling much easier.
the speakers for the rockford fosgate PBRx4 have to be 4ohm.
I already have polk audio marine db651s slimlines installed. they were a PITA imho. the adapter installation. but there are several 4 ohm options, more than any other. there might be an easier and therefore better kit on the market.
starting from scratch, either polk audio db521's for easiest type installation or maybe something else with mega magnets.
for me, since I'm already down the path, the db651's sound great.
PBR300x4 - $160 shipped
polk audio speakers - about $55/pair
adaptor rings - $40/pair
wiring kit - $20
assorted connectors/mocap/3m tape - $10
note: PBR300 has voltage sensor turn on using speaker or hi level inputs and DOESN'T REQUIRE remote power to be connected.
I am going to ISOLATE the unused speaker outputs by wrapping them in the 3M vinyl tape they sell at home depot.