You will receive both digital PDFs - the 5E and the Pathfinder version - and all stretch goals we come up with. You will also receive a special acknowledgement in the product's credits. In addition, a name of your choice (within reason) will be listed as a possible NPC name, just in case the DM needs to create another NPC at the spur of the moment.
If we do go ahead with print versions (don't know yet), you will receive a link to acquire the "print on demand" versions at the cost of printing and shipping.
In addition to everything listed above, we will work with you as best we can to include an NPC of your design (within limits) as a party guest, complete with appearance, mannerisms, background, and anything else necessary for the players to interact with (so long as it complies with licensing and publishing restrictions). He may or may not be integral to the main plot; that all depends on how much the party or the DM wants to involve them.