125
cu ft of damplifier sure would be a lot, 125 sq ft be much better
I think you said to assume that you have no wiring??
I would go with a 1/0 run from the batter to the amps with a distrobution block splitting to a run of 1/0 to the 1500D and a 4ga to the 100.4. Will also need turn on lead wire, at least 6 channels of RCA wires (can be in any combination of 3 -2channel, 1 4-channel with 1 2-channel) Unless you are planning on bridging the 100.4 then you will only need to feed it with 2 channels of RCA. Then you will also need grounds, 1/0 out of the 1500D and 4ga out of the 100.4. Not sure what you are planning on speaker wire, can be as simple as going from the amp to behind the HU and hooking into the factor wires or running 100% new speaker wire. I used about 80ft of speaker wire in my truck, but I have the amps at the back wall and had the crossovers there too but am now running active. Crossovers in the doors or closer to the speakers would cut down on how much speaker wire you need.
I am thinking the runs in my truck would be a little bit longer than the runs in your truck. I used about 18ft of 1/0 power from the drivers side batter, along the drivers side frame rail and into the back of the cab. 19ft RCA's left me with about 2ft left over in the dash after running from the back wall of the truck. Extra can always be coiled up or slacked off somewhere though but too short and your screwed //content.invisioncic.com/y282845/emoticons/mad.gif.c18f003ab0ef8a0d9c27ca78d77a6392.gif Also get a wiring harness adapter and dash kit for your truck to install the HU.
Not sure if I saw in your box a terminal cup or something for hooking up the sub. You could run the wires through the port but in my opinion it looks hack, could also go as simple as drilling some holes and using a combination of nuts bolts and washers to hook it all up or some sort of terminal cup. With the power your running though I would think a decent terminal cup would be needed or go with the bolt/nut setup.
I think that should cover most all of the miscellaneous things. check out
http://www.knuconceptz.com for wire or hunt
ebay for the Kicker PKD1 kit. Kicker stuff is REALLY nice wire but with that kit you will need to buy at least some RCA and speaker wire, while at knu you can custom build your own kit and get exactly what you want/need and its good wire at a good price.
Otherwise looks like you got all the other items you need.
