Upgrade the lens in my Surefire E2D?

I've been working on modding my E2D for the past couple weeks and I started fiddling with it and I noticed that the o ring around the lens (pre-2003 round window looking lens) had slid off the lens and wasn't creating a good seal. So, I then attempted to remove the lens and fix the O ring but while re installing it and I chipped the lens(terribly) and I was wondering if I there was anywhere on the web I could find a UCL or possibly an aspheric(if that would even work, I know nothing about aspherics) to replace it.
I'm also considering replacing the bezel ring with a stainless steel smooth one if I could find one. Id consider any other recommendations.. I already bought an LED drop in to replace the incandescent bulb.

If I find a 22mm lens it should work, correct? How do I replace the ultra thin o ring around the lens with out in moving during installation? Thanks for listening guys!