Unfortunately, The choices I am currently looking at don't have built in 3G/4G.
I like the look of the XPS 13.
There is a version with Ubuntu pre-installed (i.e. no Windows) with touch screen from US $1,349.00. It is linked to from Dell's Australia page:
Which then takes you to the US site:
...and it appears they don't deliver to Australia.
The following seems to be the closest I can find in Australia (AUD $1,399.99). although it comes with Windows and antivirus software:
Similar laptops (with Windows) from competitors include:
This could be a really good option, although it is hasn't been released yet, and I don't see anything about it being released in Australia: