TV, DVD player, and nintendo gamecube

Hey fellas, just a few quick and easy questions. Im going to be installing a TV, DVD player, and a nintendo gamecube in my car soon. The TV, and DVD player are both car audio stuff, so thats going to be running off the standard car feeds. I was wondering though, how much current the power inverter draws? I'm thinking about a 3-4 hundred watt inverter. Nothing major, just enough to power the game cube. Also, how much current would the TV and DVD Player draw? I need to know so I can figure out how big of an alternator to get. thanks. 1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp

The inverter will probably have a fuse right on it or inside of it. This will give you a good idea of how much current it could draw at the max. Unless your planning on installing a big system down the road I wouldn't upgrade the alternator for just a tv/dvd/gamecube install. Good luck, Mike