Stay away from anything that has to use a rechargable battery. You want to keep it simple if you are not fending for yourself. Simply put, if you are going to festivals, you want portability. make sure that whatever you end up with takes flash cards (SD cards) and regular alkaline batteries or you are screwed in the field.
Personally, I have your easy way out if you'd like. I recently received a Zoom H2 as a gift and have no use for it. If you want to buy it, I will sell it to you for $160.00 delivered. It is brand new and never removed from its original box. This recorder, or another like it, would be best for your needs.