whelen led slimlighter

Hello All - New to forums and had a question. As a volunteer emergency response professional, I am trying to install emergency lights in my vehicle. The LED lights I have purchase are the Whelen Slimlighters as listed here http://www.whelen.com/_AUTOMOTIVE/details_prod.php?head_id=8&cat_id=64&prod_id=295 They come with cig lighter plugs. However with the attempt to install 4 separate light fixtures in the vehicle I would like eliminate the cig lighter plugs and place them into one switch box to install under the dash. I have purchase a little project box from Radio Shack and switches and fuse box from the auto parts store. My questions are, 1. can I wire it in the following way? 2. What size fuses and wire gauge would I need to use? I would like to have one 12V source coming into the switch box to a master switch. That master switch would control master power. Then I would like to have 4 sublevel switches that would control each separate light. The master switch would be connected to a fuse box which distributes power to each sublevel switch. Of course each sublevel switch controls each individual light. Whelen states that each light is 12VDC / 3 Amps and within the Cig lighter switch has a 12VDC / 8 Amp fuse. Would I need a master fuse prior to the master switch? Any help would be appreciated.

If you are tapping a source of "switched" power; that circuit will most likely have a fuse inline already, so there is not really a need to fuse it again, but if you are running to the battery you MUST fuse anything coming off it within 18". LED lights don't draw a whole lot of power - 3amps on each x4 = 12amp total draw (probably not even that much). Depending on the length of the wire (I'd say a 16-18 AWG wire would be ok for a shorter run). Giddyup

If you do not plan on individually fusing wires, you need to use wire larger than 18Ga.  18 Ga. wire is rated for no more than 10 amps.  16 Ga. would be a safer choice. 16 Ga. is rated for 15 amps.   I would not connect possible 12 amps worth of equipment to an 8 amp circuit.  I would never increase the fuse size on any vehicle.  I know that 12 amps of current is not a lot of current, but I would still run a power wire directly to the battery and use a relay to switch that circuit on when the key is turned on. 

In defense of my 18 guage wire recommendation I did a further detailed inspection of the manual, and found out I was right about their current draw (states .5amps per unit in the pdf)--- LEDs don't draw much current at all. I bought a 6" under-car LED strip that shipped with ~20 gauge wire. You'll be drawing 2 amps - therefor 18 gauge switched power is fine. Start hooking anything else up and you'll definitely want larger, but like I said "minimum 18-16". The fuse protects the wire downstream of it. You want that fuse as close to the power source as possible (most switched power sources are fused at the factory fuse box in the kick panel). Git-Er-Done