Possible Power Problems?

I own a 93 Honda Civic, and I want to install a PS2. I also want to be able to plug in my Cell Phone and possibly my Dell Axim(PocketPC). I also have a PS1 power adapter that plugs into the cig lighter, and I know that you can use the normal power cables interchangably between PS1 and PS2, so this should work right? Or would a 3 cig lighter plug be good enough to power all 3? Or should I buy a 300 watt Inverter and plug my ps2 into that and then just buy a dual cig lighter and plug my cell phone and Axim into that? In doing this would I need to upgrade anything else? Thanks in advance

My main concern:

I would get a 400w inverter and hard wire it. 400w  inverter because they come with two outlets which you can use to power your PS2 and Axim.  Then you would have your cig outlet for your cell phone.  

Ed