low doc-- u have to pay 40% as deposit and get the left 60% loan from bank. But the interest rate will not be as good if it's low doc
U can find a broker to calculate it. U might be able to get loan from bank if the rental return of the new house is high enough. Of course u have to prove that. U can have a try anyway if you think it's a good investment property.
However, given ur wife is not working pls. don't overestimate the return of the property and your inflows and underestimate the maintenance fee of the properties.