Don't forget the UK Markets!
I think this is an excellent idea, because I tried creating a model railway using Fixed track but the straights were too long and curved when I put a curve next to them :'( .
So, for the UK,
Peco/Hornby Setrack (2-rail, black sleepers with chrome rail).
3 rail is not used the UK anymore, so it would be useless. UK 3 rail looks different to US.
Anyways, as I said, excellent idea and can fill a huge gap in the Trainz world.
Also model railway baseboards + rule for analouge/dcc operation.