as for the power i have one of these
http://www.ebay.co.uk/itm/Cycling-B...K_SportGoods_CyclAcces_RL&hash=item3f2f277aab
i find it very good the usb socket is a bit big but i fitted it under the seat and run a usb extension to the handlebars iv had it for a few years now and its never let me down.
as for the water purification i used to use iodine liquid a small bottle can last for months i find it better than the tablets as i can use what i need rather than the tablets. but i also have a water pack with a removerbal water filter look here
http://www.geigerrig.com/ i swear by this system iv had a few others but i think this one is best iv had mine for a good 3 years now and iv never had any issues with it and the best thing of all because you can pressurise it and spray the water it doubles up as a shower wash station even to clean your bike when its muddy.
i also carry
http://www.ebay.co.uk/itm/Webtex-Su...gGoods_HikingEquipment_RL&hash=item35beb4b65d one of these i normily carry it empty and only fill it when i need to its more of a back up but is quick and easy to use
and as for sleeping bags i carry a 2 season cheap bag and i also carry a proper army issue wool blanket. the blanket can be used on its own or with the sleeping bag. also you can with a few sticks and string use the blanket as a seat or just throw it on the floor as a mat and being pure wool it drys easy and quite quick and even when wet it still keeps you warm i think its something like 80% insulation even when wet. the only drawback with wool blankets are they are heavey about 4 to 5kg double that if it gets wet but brilliant and worth the weight. iv been out wild camping in -21 is the coldest so far and i was warm and toasty warped in my wool blanket lol.
hope thats been some help