what is the most portable air conditioning with minimal electricity needed for a camping trip?

Question

I am planning a cross country (us) cycle/backpacking/camping trip for myself and my kids.  I hope to set off in early June as soon as school is out.  Two of them have autism (one of which is severely involved, the other high functioning) and the third will be two in april.  So, i need something extremely lightweight, portable and able to run off nature as much as possible.  this is not for a nightly basis but for extreme circumstances when the kids (and myself of course) will need some relief.  this adventure will take us throughout the next year + through rugged and extreme conditions from time to time.  We will also be cycling, myself and my 10yr-old son will be the only peddlers.  My oldest is too severe (disabled) to assist and obviously the 2-yr-old can't help much.  so we have to minimize weight as much as possible but have enough supplies to keep us safe and healthy.  I am contemplating a 600amp power pack to use for nightly computer logging, occasional heating, occasional cooling (undetermined unit so far), occasional movie watching (dvds on comp), and mp3 and track phone charging.  This pack can be hooked to a solar pannel for charging during the days while we ride and the pack weighs about 30lbs (another small child), but it also includes am/fm radio, alarm clock, ac and dc outlets, some models even have air compressors.  Obviously we will have the smabeginningpumps due to tire repairs and air matress needs but i thought for 30lbs this includes several items in one and can be charged with solar.  it can also be charged with a cord when access to plug is available.  The tent we've decided on is rather large (up to 8 peeps) for the 4 of us.  We have quite the convoy of family chariot trikes and trailers assembled.  I really want to have a cooling device for those exhausting days - which i'm sure we will have many of, especially in the beginning until our bodies adjust.  No need to cool the entire tent but an area to create relief.  Any advice on cooling and power units that meet these needs would be greatly appreciated.

Val