I suggest the Southeastern Mainline from London Charring Cross/ Cannon Street to as far as Tonbridge. It will include Lewisham Station too. The 375 and 376 Electrostars, and 465 and 466 Networkers. Also, with the 465 and 466 Networkers, it would be lovely to drive 6 and 10 car services from London to Tonbridge as well as 4 and 8. With the 375, 12 car train services too as well as 8 and 4 car. The 376, 5 car and 10 car services. Also, the Class 66 between Grove Park Freight Yard and Tonbridge Freight Yard. NOTE: I apologise if you think it is a bad suggestion, but this was only an idea.
Good suggestion, I really want Charing X in TSW because it's a station I get off at a lot and it's never even been in TS. Might not look great in TSW though because of all the landmarks you can see near the London stations that will need custom builds like the Shard at LDN Bridge and London Eye at CHX