How about giving Qasair/Condari a call. Head office is in VIC which should be close enough for Ballarat. http://www.condari.com.au/custom-made-special-rangehoods/

We got a custom made flat pack kitchen from a company in Queanbeyan, not sure of where you are. Much better quality, Australian made and you can get exactly the dimensions you want, which is important for a kitchen with so many corners. You might be better off holding on until you get a little bit more money together and put the kitchen in the existing living room and opening up the kitchen dining to the new kitchen for a better flow out to the backyard. The room looks lovely and well lit with high ceilings, paint it and change the handles now and don't miss the chance to do something a bit better later on. Does not solve the dishwasher question though. .....

Good question! Maybe a metal fabricator may know?

You can get slim range hoods that generally fit into the wall cabinets ours were approx 40cm deep which housed the complete operation, our plumber ran a 6 or so inch flexable ducting into the roof cavity and out under the eaves. Most brands make these. A photo would be helpful. https://www.thegoodguys.com.au/omega-52cm-undermount-rangehood-oru50x?CAWELAID=620013790000422290&CAGPSPN=pla&CAAGID=21711678566&CATCI=pla-376401441757&gclid=CjwKCAjw0qLOBRBUEiwAMG5xMNN63iJr0n0Bnxf31-Gt0t5s0vERt_lOwOYkC6uzovf9TDWwawry9RoCgxQQAvD_BwE&gclsrc=aw.ds&dclid=CLOv9erawdYCFc0slgodE5oLHg Where we didn't have wall cabinets we had tall boxes of stainless look laminate built up to the ceiling which contained the extraction unit, which was approx 30-40cm's and extraction ducting cheers