Hello Stick,
I used to use cold casting resins from this company.
http://rudolphbros.com/products/product.php?c=7&p=16 they are not close to you but you may be able to get some information from their web site.
Pure urethane resins are tough and impact resistant, but hard on silicone molds since the urethane material sticks tenaciously to anything it touches. Most can be colored to match your sample. A modified or filled urethane resin like their "Pro Cast" resins is easy on molds, easy to work with, work fast and shrinkage is minimal, but it is not nearly as impact resistant and not good for color. Epoxy casting resins can also be a possibility also, but is harder to work with and hard to color.