Definitely wise to do some loading before you commit to spending your dollars.
There are only a few in the country that can provide the rating and have been listed above, another is Super Spread at Deniliquin NSW. All of them are very competent.
As said early it would be prudent to wait till there is a bit of an up swing, however if you are committed to going this way come hell or high water then jump in and paddle like hell.
An Ag rating is viewed favourably by other industries such as Survey, Powerline/Pipeline Patrols etc.
Good luck
M