Why 8.0 Purchase, Need Help With New Lens....

[Fakir]

Hi Folks..

I recently acquired a near perfect Oakley Why 8.0.
The sunnies don't fit me correctly but I always wanted to swap out the lenses (these have a few scratches) anyways.

I need help with a few aspects here.

1. Since I am quite new to the forum and the donor lens reference sheet is non-existent on the forum, any pointers?
2. Being a rimless frame, how critical would the base curvature, etc for selection be?
3. I want to be able to go to the optometrist with the existing frame and donor lens, try on a pair that fits me best and use it as a model to make what I give them.

Would this be the right approach.
Thanks.