Your suppliers will always have the details of potential (laboratory analysis) extract. You should be able to get details of all the products they supply, in the format you need.
This applies to sugars, malts, and other dry adjuncts
The achievable extract will depend on the equipment used, and the process used. This will vary from over 100 % of lab extract (honest - it does happen) down to..... well pick your %age.
Sorry, but I don't have a wide range of extracts available at present, but will keep an eye out (I don't do the extracts regulalry any more)