I would like to see what i need to finish my collection but i am not sure what i am missing or needing.

Thanks

go to the minisite ( http://www.fantasyflightgames.com/edge_minisite.asp?eidm=12&enmi=Mutant%20Chronicles ) and click products. that will show you everything they released. or if you have bought or buy a lost legion set ( http://store.fantasyflightgames.com/productdetails.cfm?SKU=MC20 ) it comes with a poster checklist.

Beyond a figure listing, is there a list of which figures are common / unique? I'm thinking about getting into MC (I know it's discontinued), and am curious about multiple commons.

same answer. you can see which ones you will have mulitples of (in either the same pack or buying different packs). There is no rarity in this game anymore.

There are unique characters (ones you can only have 1x of and not 4x of in one army list). They are: Golgotha, Max Stiener, Mitch Hunter, Karack the Keeper, Archinquisitor Nikodemus, and Alakhai the Cunning