hi, i can offer some advice as we just went for pre-approval today...

DH is the only income earner and we have savings to cover 20% of the deposit (after we take out the roughly $26,000 in fees and charges like stamp duty). we are also first home buyers.

we found that in relation to last year (when we first started enquiring) the banks have become alot more conservative in relation to how much they lend. for us the amount dropped by $200K despite the fact that we are now earning more!
in all honesty though, we feel more comfortable with this. the low interest rate and the loan amount we are asking for means only a $100 difference a week between the mortgage and the rent. this time last year it was a completely different picture and threatened to really impact on our lifestyle ITMS.

so although it kinda sucks not being able to borrow so much, it is also a little reassuring to know that we feel 'safer' with the amount we have.

It shouldnt be a problem that your DH has only been working there for 6 months. they usually just want 3 payslips...so that time-frame should hopefully cover it.