KS Reward Structuring
One perk that I kind of like is something like the "OBI magic box". Let us surprize you ;) (in there you put all what is digitally produced or cheap: for 100$ they get all the videos, all the access to webinars, all the ebooks, and the postal cards. Maybe the t-shirt depending on the price.
Poster might be more expensive. I would go for a simple postcard matrix. Signed by you with an update on the project. Easier/cheaper to Print and send.
Matt