Now available is Eureka models NSWR 620/720 2car DMU in a variety of liveries.
It has a good level of detail and also can come with optional sound. It can also come factory weathered as an option. Non sound equiped models will come as DCC ready so you can fit your own decoder. An example of this unit was reviewed in May's Continental Modeller and they were impressed with it.
This retails for the sum of $395 Aus add an extra $25 for factory weathering and $99 for Digital sound, th QSI version.
The website has a sound clip you can listen to.