O Scale Indian Train Models

I was wondering if anyone has suggestions on how to get miniature O Scale models of Indian engines and trains.

Abhishek and I are quite fascinated with the Lionel models that we have seen in the US. What we want to do is to build a collection of Indian trains. So far, Abhishek has been playing with the Thomas wooden tracks, but I guess its time for him to graduate!

Any idea on where to find such models?

Thanks in advance.