Hi MP,
You said
"How would this be possible when the LOC will then include the PPoR and the IP together as one?"
I don't think you should increase your PPOR LOC to include an IP. I have asked alot of ppl regarding increasing my LOC just for the deposit of an IP, then getting a separate IP loan and met a resounding "Keep the IP and PPOR separate".
The reason is it would be create more work for your accountant now and for as long as you keep the IP (maybe forever) and to clearly show a difference btwn the deductable and non-deductable loan for the ATO.
When I asked the ANZ if i could have a 2nd LOC instead they said it was no problem at all. Then my loans costs and ongoing fees would be clearly shown as an investment not personal. In your case your 2nd LOC could buy your IP in one hit and your above question would be answered as they are 2 separate loans.
Also, a 2nd LOC for IP loan may not be your best option as it will be a slightly higher interest rate, do you really want to pay more for convenience? why not shop around first.
Another thing, even if you have the 2 separate loans, moving all the rent money from the IP to your PPOR to pay the non-deductable loan (which is what I assume your saying) is still being tested by the ATO in court, so you might want to read past posts on this before doing it.
Lastly, why not email some ppl on this forum such as mortgage brokers - Rolf and Simon on what loans they can do for you, it could be well worth the email before you start.
Chris