a 200 watt inverter usually can just plug into the cigeratte lighter, so power consumption shouldnt be a concern. If you plan to mount it in the trunk, just power it like you would a normal amp, 10 gauge wire should be plenty, but see what the inverter recomends if anything. Yeah, you can plug a power strip into it, just be sure that the components that are on do not exceed the power ratings for the inverter.

All the components that you are using should list the power consumption on the back panels... or in the manuals. A 13" TV dosent draw that much power... maybe like 50 watts at the most.