Welcome aboard Oscar!
Go the GQ 4.2 mate one of the best 4x4s ever made. We've got a GU4.2 being a little bigger for our family of 4 and get around 600kms per 80L tank on the flat ground. GQ's being lighter will go even better on fuel. Once you've got some extra money down the track you can do some amazing power ups on the 4.2s.
Cheers!