I'll echo what's been said already, that's an unbelievable collection of parts. Wow.
I love the wide variety of handlebars out there today and I would run dozens of them on different bikes, but for me, the Hillborne should run one of two bars: Nitto Albatross or Nitto Noodle, and of course this depends on whether you want it to be an upright bar bike, or a drop bar bike. In either case it should run Dura Ace bar end shifters (9spd or 10spd), and a Shimano drivetrain with wide range (double or triple, and at least an 11-32 cassette). I don't mean these as limitations, it's just how I would build a Sam over and over again. The irony is I'm running Campy on my own Sam, but if I were to do it again, this would be what I'd do.
Simple but effect parts go the furthest on a Sam imo. Here's what I would do:
- Deore or XT hubs to Velocity Atlas rims (optional: SP dynamo front hub)
- Velo Orange fenders with whatever tires tickle your fancy (I'd run the Rene Herse tire of suitable size in standard casing)
- Bar-end shifters operating Shimano Deore-level derailleurs
- Sugino triple crankset, Shimano 11-32-ish cassette
- MKS pedals of your choosing
- Nitto Albatross handlebar attached to a Technomic / Tallux stem
- Paul Racer centerpulls (expensive, but a good place to put extra money)
- Nitto Marks rack up front; maybe an RBW51 out back