Hi Susie,
In my experience it is best to have your properties as stand alone. I have five stand alone properties with the same lender, all were 5%dep.With this lender if you have five loans they waiver the application fee on all and charge a flat $295 per annum.That is , no account fees or charges etc on all five loans plus a lot of other benefits. My point being ,do your homework , get an excellent broker and make the banks bid for your business.Be wary of a lender who insists that they need more than one property to secure the loan.
Hope this helps.