err .. I can't say I'm good with page designing, and filling info. 98% of character pages are empty on my wiki too if you realize :) But I can help creating some characters, with a little info, and then I coul leave the rest to you, so that you can shape the characters according to your story.
Q1- Do all doppelgangers have to be the ones we've heard of on the show, or do you want me to make up some?
Q2- How many doppelgangers of which character(s) do you want?
Q3- Do all doppelgangers have to be alive and present at this current timeline, or can some be long dead?