im not sure i understand what youre saying... are you saying you want to power a laptop AND your monitor off of one cigarette outlet?
-personally, i would figure out a way to wire your monitor off of a more stable 12V line than the car's battery. as you have read, the voltage fluctuates a lot with the battery, and although your monitor can take it, it prefers not to and will lengthen its life if you give it a stable 12V.
-as for the laptop, you could power it by a cigarette outlet, just doesnt make for a clean installation. also, if the outlet isnt switched, you might have to worry about it draining your battery while youre not using the laptop.
-dont know anything about Webmaster's laptop kit so i cant help you there.
>>hope some of this helps. again, not sure if i answered your question(s)
EDIT: just found this thread 2 threads below this one:
http://www.mp3car.com/vbulletin/powe...g-diagram.html
>similar set up.