Re: Humbucker for Strat?
Traditionally, as you probably know, 250K are used for SC's, and 500k are used for HBers. You want to use 250K for the master volume on an HSS strat for the SC's sake. That helps tame some of the highs on the bridge pickup too. Using a 500k for the tone on the bridge HBer is an effective compromise solution. You can also use a 500K tone for the neck pickup to make it a bit brighter if you want.
On an HSS strat you usually have a master volume and two tones. One of the tones is for the bridge humbucker so you can adjust the tone of the bridge PU seperate from the neck and middle single coils. The other tone is usually assigned to the neck single coil. ( This is different from the original strat set up from 1954 of one tone each for the neck and middle and no tone for the bridge pickup, but in those days amps and speakers wern't as bright as they are now.)
It is also common to use no tone control on a bridge humbucker as long the volume pot is 250k, but then you don't have the option of rolling back the highs a bit on the bridge pickup if it's a tad bright at a gig.