Ended up getting official Nokia "emergency charger" (1 AA battery, this definitely has booster), need to test it to see if it is sufficient for my needs (and if not I'll take it apart to check a few things [like what ICs it uses...])

Edit: Also found the spec (http://sw.nokia.com/id/3378ff2b-4016...on_v1_2_en.pdf) plenty of good info (though I wonder how much smarts does the power supply really need and how much of the actual charging logic is built-in to the devices)