Advice wanted on how to get first loan

Hi There,
My youngest brother (21) has just got his act together and decided to buy a house. He hasn’t got a very high salary ($33,500) as he is a 3rd year apprentice plumber, but his pay increases substantially each year.
He has savings of almost $15K and this will be his first house and so he will be applicable for the 1st home owners grant and no stamp duty.
THis is where he is doing it a bit different.
He would like to buy a 3 bedroomer house and rent out the other two rooms for $100 each. He will also be renovating the house as he is really handy with tools and has a lot of tradie mates.
He just went to Wizard home loans who said they could lend him a max of $170K. My brother would like to buy a house for about $230K. Wizard said they couldn’t take rent into consideration as it was his first house. They also said the repayments would be really high as they calculated on a P&I loan. My brother would like an interest only loan though.
I know when I bought my first house I was on $38K and the amount lenders would give me varied from $150K to $310K. These days, it seems a lot easier to find a mortgage broker who understands what he is trying to do rather than trek to each bank like I did.
Does anyone know of any mortgage brokers who understand the concept of investing and living in the house at the same time and who would be willing to give him a go? His savings record is impeccable and he is really keen to do what I did and renovate the first house, increase the equity and do it again in the future.
He would also like to pay as little deposit as possible and just pay the LMI.
Can someone with the knowledge please help??