Long inner labia
What are the Labia Minora? (with pictures)
The most effective are bio-identical.
I suuggest you don't be so concerned about the length of your inner lips.
Here's the thing to know: many of the people on those sites have not seen a lot of labia in their lives, and some have likely never seen any, ever.
One must use caution in augmenting majora with significant skin redundancy, as an unacceptable degree of bulging and labial prominence may result.