Biltwell HB Seat, just got my bike finished from the winter so no real ride reports yet. Felt pretty good on the first couple hundred miles, we'll see how it is for the passenger in the future.
Seats come up frequently, so to look back over what other members have done use Search for 'seats'. Most popular for 2-up work are Mustang and Sundowner.
Hutch's was a one off piece he built using old wizzard magic and pixy dust.
Actually he has a build thread for his entire bike here if you'd like(link below). I don't recall what page exactly has the details regarding the sissy bar but he built it himself. It's pretty damn nice.