I'm for iodine, or one of the other chemical water purifiers. You are not going to need to filter a lot of water, and the weight of the pump (and the pumping) is just a nuisance. However, a bottle of iodine tablets weighs almost nothing, so if you want to be paranoid.

Seeker, let me introduce me to your new friend, able to survive, and thrive in a rolling boil. Don't think it'll make you sick though.