Hey, I was wondering if anyone knows of any good pickups that give sustain as well as any pickups that could produce a good feedback (any tips and techniques would be greatly appreciated!...like the band, Boston, feedback, though I realize Tom Scholz is a genius).

I have an Ibanez SA series guitar (H-S-S) and I want to change the bridge pickup. So, anything that you suggest, I'd appreciate!
Sustain will be more down to your guitar's construction and your technique, but if you NEED insane sustain, get a Fernandes Sustainer to replace your neck singlecoil.

As for feedback, any seriously hot pickup should do it :\ Don't hold me to that though, because I've never been into trying to get loads of feedback.. it just happens for me - all of my EMGs are bastards for that if I'm not careful.
Yeah, I heard about that pickup.
I have a guitar with EMG's but I have never actually been able to get any real feedback from them.