Hey Mike,
Lots of info on both questions here on the site. I'll answer on the seat. Again, lots of options but I went with the Sundowner dual tour model from HD two years and 20,000 miles ago and still love it. Wasn't out much moola and I utilized the loaner/demo seat program riding on the demo for a week before purchasing. That saved me quite a bit as most aftermarket folks won't let you return a custom made seat. I've had three Corbin seats on various bikes over the years and like them for looks and build quality. I just didn't want to spend another $700 to $1,200 on a seat this time around.
Pipes? I went with the gutted/de-catted stock header because I like the stock look. Fulsac is the best all around choice for performance and keeping that stock look.
Good luck and congrats on the new bike. Love dem street glides.....however, my eyes are beginning to wander a bit toward something in Abyss blue and a fixed faring......
