pots with bart dual coils and aguilar obp3

so i got a new bass with bartolini dual coil pickups with a switch to go between single coil and parallel Hum canceling modes, i might replace that and get me two series/parallel/single coil 3 way switches.. one for each pickup. so i have even more options (maybe)

anyway that said, i've always read 250k works well for single coils and 500k for hum buckers. now because i often use both, which one do i want? i also read 500k is for a more wide open sound, which sounds like what i want. so should i get 500k pots? the treble does sound a little "tame" to me and i wont mind "more bright"

funny things is right now.. my volume pot is A250k but the EQ pots are B50k (?) is that even right? thats what i can ready.

asking because am going to order a push pull pot so i can get rid of the active passive switch i have and move that toggle over to the pot which saves me from drilling a new hole into the bass. and i also see two kinds of push pull pots .. CTS and Alpha.. which one do i want out of the two? all other pots on my bass are not cts and again do i want a 500k push pull or 250k push pull? will changing one single (volume) pot to 500k make any difference?

 

Also, any clue as to where can I find stackted B50k linear pots?