I think London fenchurch Street to Southend would be a good route with the class 357 and class 66 and possibly of one of the old network South East they used to use as an add on loco!
OMG YES!! That is my local line and I have put in Greater Anglia from Liverpool St to Southend Vic and OMG YES THEY BOTH ARE GREAT!!
Some more detail here: https://forums.dovetailgames.com/threads/london-fenchurch-to-shoeburyness.24754/
I think the fenchurch street via grays and tilbury would work best as you have the freight trains from Tilbury docks and Dagenham docks and the new docks at corringham they could do extra variety in the scenarios, and as they use the same freight trains that are already in GWR add on, it saves on modelling for that lol, and I agree the it’s a great idea as this line is famous as it has been ferrying the east ends population to Southend since Victorian times hence when they renamed the line they called it c2c “city 2 coast”
