Stand By, Ready
I don't think there was a whole lot of Kickstarter exclusive stuff either, so if you wait for the retail edition, I don't think you will be missing out on much.
The Kickstarter exclusives in Sellsword level were
8 Kickstarter exclusive Envoy Mission cards
1 Sellsword pre-painted miniature on flight stand & Sellsword card.
1 "Dev Kit" including: 3 empty sectors, 3 empty flight stands, 1 set of 12 blank outfits, for your modding pleasure.
Everything else was an upgrade to the basic game.