Thanks everyone (Especially Serenation) for this thread. I'm trying to piece together what information I can about Dr Ives surgery and this has been an excellent help.
I confirmed (what Cindy has already said) that the medicare numbers are as follows:
"You need to be covered for the item numbers of 45563, 37405, 37342, 35565, 30644 x2, 45206 x2 to be performed at Masada Private Hospital plus a 10 night stay in hospital. You also need to ensure you have no psychiatric restrictions on your level of cover."
I have also updated my cover to the top for HIF. However this won't come into full effect till August 2016. I requested more information from HIF and they said this:
"Further to this, as far as the item numbers you have provided, your level of cover will pay benefits towards the surgery, however it does fall under the 12 month waiting periods and would be subject to the fund's Pre-Existing Conditions rulings. If you have this surgery before the 5th October, the surgery would be paid at your previous fund's level of cover and also requires approval by Medicare. The full 12 month waiting periods on your hospital cover will expire on the 5th of August 2016."
...That just made things even more confusing however.