What is the difference between these trunk lids? I can't really tell from looking at them. Is it a quality/fitment thing?

Here's some examples:
AutoKits

Outcast Garage

Also, does anyone have any experience/recommendations/pictures of the larger duckbill trunks installed on THEIR OWN cars? Thanks for your help!

 

Have you checked out RB Trunk ? A lit of DFW guys use his stuff.

 

duckbill

 

Do you have any more pictures of that RB trunk?

 

Asking me?