That does look nice.
I'm a big fan of the flashing brake light - the more people I can keep a safe distance away from my kazoo the better I feel.
Take a look at Robert's thread for some links; 100 THREADS all GS/GSA owners should read. --- #49. I WANT TO MAKE MY BIKE MORE VISIBLE...WHAT ARE MY OPTIONS?
I have the HyperLites running from the Grn/Blue wire on the diagnostic plug to power the controller. The P3's from Skenes do look bigger and brighter - but more expensive too.
One farkle I've been looking into lately has been a way to connect to the high beam wire to trip the high beam bypass system or controller for aux lighting. Some people want to use a posi-tap on the high beam wire which is fine; but the best idea that I've seen so far is the one from Clearwater Lights used on the their Krista's setup; which uses a male / female plug configuraton that has an extra wire coming out of it to trigger the controller. Truly a plug and play setup. Nice. They don't sell components (otherwise I would have bought their wiring kit), so I'm on a hunt to find compatible plugs for the back of that headlight assembly.
The bike looks good - looking forward to round two too...