Stereo install questions

[DJ20XD]

Please help. Im am installing this system in a boat. I have 4 Polk MMC Momo650 speakers to install on ft channels powered by Clarion APX480M amp,2 Polk Momo690 speakers for rear channel powered by Clarion APX280M amp and 1 Bazooka 10inch 200watt powered tube sub. I have never installed a stereo before, could anyone help with detailed wiring help. My biggest questions are do I run 2 signal cables from the HU to the ft speaker amp or is there a way of splitting the signal at the amp? and also the Sony HU I would like to use has 2 pre amp outs. 1 FT and 1 RR/sub selectable, where do I get a sub signal if I use the Rr channel to the rear speaker amp? Sorry for the long post. Any help appreciated.
DJ

[black magic]

for the front, you can use a splitter like you said. But there is another easier and cheaper solution. run 1 signal cable from the hu to the amp.

What you would do is plug it into the front channel on the amp. But then you would also need another (very short) signal cable. You would use this 2nd cable to connect the front output on the amp to the input for the rear channels. viola! Now you have 4 channels for the front.