if you are getting the JB pickup, i'd recommend getting the Jazz pickup to go with it. My friend explained to me because the Jazz and the JB are the same type of magnet, they will work better together
edit: wait, nevermind. the Jazz and the '59 are the same type of magnet. sorry about that. I remember now I was debating between the Jazz and the Pearly Gate pickup. sorry for the misinformation.
http://www.seymourduncan.com/website/SDToneWizard/hummer.htm
if you goto that link, you can download samples of what the pickups sounds like