Amplifier Cabling

[DCBT]

Hi learned people,
I'm looking to install a 5 channel amplifier in the boot to initially feed the front and rear speakers and ultimately the obligatory sub in the helmet holder.
Would you be able to tell me the best cable route from the boot to the head unit for the 3 sets of RCA cables and from the boot to the front and rear speakers?
Is there a suitable point in the fuse box to pick up the fused direct power connection or should it be run through the car to the battery?

Thanks for your help and advice

[ridds]

I stuffed all mine under the central tunnel cover from memory. Power feed I took from the battery but then I do have half a ton of amplifiers in the boot and 1.2 kW of amplification....