you should really look at investing in a good power adaptor with daisy chain, the BOss PSA is pretty good, i dont notice any hum really.
in terms of batteries, i use energiser or duracell, kasi sometimes you may have a new but cheap battery, that will cause your effects to sound crap because its not getting the right amount of juice.
if i were you i'd buy a PSA, magastos in the long run kung puro batteries..