1. Aero Darien jacket & pants -- I have a one-piece Roadcrafter too, but the Darien is my choice for LD riding.
2. Gerbings jacket -- There are two kinds of (serious) riders. Those who own electric garments and those that will.
3. GIVI bags -- Tough, waterproof, secure -- Turns nearly any kind of bike into a touring bike. Once you have a bike with hard luggage you'll never go back.
4. Corbin seats -- Some folks think that Corbins are "too haaarrd"; those people need to toughen their butts up. Day 3 on a long trip is when you really appreciate a Corbin.
5. Best bang for the buck -- Kimpex or Dual Star heated grip kits.
6. Best bang for the buck 2 -- Cheapo driving lights. On a strange road at night, more light is better.
7. Pro-Gel Grips -- Thin, flexible, grippy -- Riding with stock grips is like fucking with a condom made out of inner tubes.
8. Best recent gear addition -- Mesh jacket. How did I ever make it through all those summers without one.