Where can I pick one or a few of these up? and could i get a big enough relay to run off of the cigarette lighter power wire and run maybe a pocketpc, 5 V GPS, 6V Handheld Scanner, and 2 Cold Cathode Lights?

lol or am i hopin for too much on one power wire / relay

I dont know about the other answers to your questions, but heres where you can find Relays: http://www.partsexpress.com

EDIT: For some reason it wont link the actual relay page (DUH) just do a search for them.

just search google. 5 pin relays can be found anywhere from rat shack to wal mart.

It all depends on the maximum combined power consumption (watts) on those items. This way you can determine what size relay & wiring to use.

I want to figure out how many amps the devices will use all together, but i need V x A = W

and all i know from the devices is voltage

or just buy a regular 40amp relay, which are easily found. run 16ga power in, 16 ga power out, then you can use 20-22 ga for the coil positive and trigger.