First you must distinguish between "sales rep" and "distributor" or "reseller". Some that call themselves "reps" are not acting for you but for themselves, which makes them either a retailer or distributor. Then you have used the term, "consignment"; to whom will you be consigning - the "rep" or the ultimate person or firm to who he "sells" the product?
True sales reps write orders that you ship and bill to the end customer, then later pay the rep a sales commission. On that % - I am not a good source for the jewelry industry, but I am an experienced rep and also, later, a manufacturer who used reps.
Sort out the actual chain of distribution before going further. And - are you related to Getreus originally from the Cleveland OH area? (Sandy Getreu??)