That is a great idea for a kit. I too am trying to build a kit and don't want to break the bank with 4000 dollars worth of stuff lying around. In regards to the water purification there is a recent thread regarding the BCB water purifying straw with photos next to an IZULA. I haven't done enough research to say they work well but what I read they seem to. I know your pressed for space, but I would recommend a space blanket. And have u considered attaching a survival bracelet to the back for the extra cordage, u could put in on your wrist when needed. I will send you one if you want one.