Haven't even tried GPS yet, but will be using either iGuidence4, or MapMonkey. MapMonkey is apperently easier to integrate with RoadRunner, the frontend that i'm using. Up-to date Australian maps will be the largest hurdle im expecting.
As for LCD's, I highly recommend Vastute.com or Mobile Computing Solutions. Both usually have sales on eBay, which is where i got my Lilliput through Vastute for $269 delivered.
I have been in contact with MCS, they are an international company, BUT, they have got a sales person in Australia, so you can email them and ask for his details, which in turn, im sure you could get it cheaper without paying some of postage costs from the USA.