Power Usage?

I’m planning on building a portable computer lab/wardriving station/fun zone with my friends this summer. Basically we’re going to convert a conversion van into a computer lab :wink:

It will have one desktop built in, a TV and a game console, plugs for laptops, a wired/wireless LAN, and maybe a webcam or two. It will also be outfitted with a GPS unit for wardriving (and an antenna).

I’ve been looking at DC->AC Inverters and I’m not sure how much Power Output I’m going to need. What do you guys think?

And also… I know wall output is 120V, but an Inverter I was looking at outputs 115V… is this close enough, or does it have to be exactly 120V?