Its really todays line but with more sets of points then currant yard, although were there years ago.
There is no NG SA stock for Trainz as far as i know. the closest thing i have found is the TRS 2004 QR C16. it is a very similar to the QR C17 which the design was used by commonwealth railways to build their NM class steam locomotives. There is also the up and coming Brill railcar being created currently which would fit in nicely. Any 3D modelers out there who would give it a try? NT's and NSU's are very basic designs, and i'd imagine not really hard to make.
The best so far, i run QR C16 + 6 or 7 SAR 313 baggage cars, or the QR C16 with some SAR freight.