The Geo-IP look up feature in EPiServer CMS 6 R2 will certainly help you achieve the functionality described in 1. and 2. Here's how: 

1. If a user hits the .com homepage and matches a "From AUS" or "From NZ" visitor group then redirect them to the appropriate site. You might want to think about the fact those users might still actually want to see that page though and use a query string to automatically stop the redirect if they browse from the local site. You can use some personalisation using the location criteria in visitor groups to prompt people to visit the NZ or AU sites if they appear to be visiting them - a bit like when you visit Amazon.com from any country outside the US.

2. You can use something like Mark Everard's personalisation engine to conditionally serve up the correct content http://personalization.codeplex.com/ 

As for the domain discussion its generally a marketing decision. What URLs are advertised? Is a .com domain seen to be less personal than a specific country domain? As far as I am aware I think having country domains (and appropriate meta tags) can help with SEO when it comes to "only show pages from NZ" in Google.

In the past I have used .com for corporate and country domains for consumers. 

Thats all for now... Hope it helps!

Thanks David.

The site we have right now is still runing CMS 6 and not CMS 6 R2. Site upgrade won't be until August 14 if I'm not mistaken.

With just CMS 6, what options do I have? Is it something we could address easily for now?

Hi,

   I am new to this concept.Can any one give the step by step process on how to identify

1. The IP Address belongs to which country

2. How to redirect the user to specified url

Thanks in advance.......even small suggestions or helpful urls are greately appreciable