Their are many many many things you can mod on a gen 1, most have already been done what you need to do is make it individual to you, that's what will make it special that's what will make it yours.
I looked a loads and found a few things that I thought hadn't been done or maybe they have who knows.
R1 forks have been done and I admit I was very close to doing them myself until a mate changed my mind and I ended up with