So, there are a few sets that work :
- DB Set XL. An outstanding set that you can find
here. It ONLY works in the temperate climate, needs an extension to work with FIRS, etc, but at least you can have electrified railways since the first vehicle (1920).
- 2cc TrainsInNML. A very, very extensive set, about 4 times more than the DB Set XL. It contains a huge damn real high amount of trains, works in all climates and starts in 1835.
- Bob's British Buses / Bob's British Random Vehicles. Good road vehicle sets that outstands most other ones.
- Polroad / Poltram. You should use both at the same time, as Polroad includes a lot of trucks and Poltram also includes freight tramways.
- Squid Ate FISH / redFISH. They have a lot of vehicles in common, but both are good, and one of them (i don't remember which) includes a freight hovercraft.
I'd reccomend you the combination DBXL / Polroad + Poltram / Squid Ate FISH. Start in 1920, so you will have most of the interesting vehicles.