Brian Hi from the other side of the pond, i started off with a conrail SD40-2 and a Santa Fe Bachmann GP40 !!!. The Bachmann loco's are good reliable runners, they are not "show pieces" but are good basic hard wearing quality, as for rolling stock Bachmann "Silver Series" wagons are fantastic runners with metal wheels and are the same basic hard wearing construction, and they come with knuckle couplers.
I'll come back to structures when my brain wakes up, but for now this was my second attempt at a depot in a small place, this kind of structure can be built from three basic kits for well under $30, buggered if i can remember the make