For on-road stuff then (i.e. SatNav) I would get the new "TomTom One", It's about $360 (JB HiFi) at the moment with the latest Whereis v14 maps installed.
If you want on and off road mapping then either the Magellan Crossover or the (to be released in the next few weeks) Magellan Triton range.
Hope this helps,
Jon

