You can find the daylight on the DLS. Search for USA SP with all boxes checked for the engine and SP DAYLIGHT, also with all the boxes checked, for the cars. They are older models but visually quite good. You might also want to check lilbs creations at http://lilbscreationz.freeforums.org/, he has a thread on his forum giving the progress he is making building a newer version.
To anyone making a new GS4. How about the Western Pacific version known as "almost Daylights", with or without the smoke deflectors?
So far there is no Trainz WP steam.