Since you are the only one having the surgery, just get PHI cover for you. But there is still a 12 month waiting period. If you pay for the surgery yourself, get PHI (before or after the surgery) then get a leak, it could be determined a pre-existing condition so you won't be covered. However long you take it out for depends, but sometimes just having the once off surgery doesn't end there.
For example: Lapaband in, lapband out, sleeve, emergency bypass, bypass revision then gallbladder removal. So that's 6 surgeries in 2 years. That's not counting the times I have been re-admitted for complications or all the tests etc. But I am also one of the lucky ones, some have been re-admitted around 3 x per month due to complications.