Stansted express would be a no brainier! It has both commuter and intercity services The trains that will operate on the line by 2022 will be the class 720/5 and 745/1 Although the c2c route would also be brilliant too! I suggest dovetail games do both routes! C2c stock include class 357 and by 2022 some 720’s will join the fleet to replace the 387’s
How about the Raritan Valley Line which introduces classic NJ Transit trains from train simulator 21. The following are ALP-45DP GP40 & F40PH NJ Transit Comet V & Bombardier Multilevel Coaches. The new locomotive is PL42AC