Some will specify distance and angles permitted. Check installation guides out

Any range hood extractor fan would be suitable. It depends on the aesthetics of your kitchen, and your budget as to which style would suit the best. Have you thought about a down draft extractor fan?

Hey I'm wondering if anyone can send me some recommendations for builders in the bendigo and Macedon Ranges area for home renovations.

What sort of cooking do you do? We looked at a house years ago and wondered about the lack of rangehood, were told it's fine because there's a window, noticed years later when it came up for sale it now has a rangehood. For people who enjpy cooking, an externally ducted rangehood is best. For a non-kitchen aesthetic, a rangehood that rises out of the bench might be an alternative but is not as effective. I don't know if there are any on the market which can be externally ducted. If not they have additional filters to regularly clean/replace. I've never understood having a less effective appliance which requires more maintenance if you can have a better and easier care appliance. I'd really work out first what functionality you require in your kitchen and then get what suits how you use your kitchen. I remember older relatives' houses from pre-rangehood days and they always had yellowed kitchen ceilings. But if you don't cook much you might get away with it, though I'd allow space for future installation for resale value. As for the building code requirements, check with your council. We've owned/rented various houses with different set-ups depending on the rules at the time and also whether the installers knew what they were doing, for example getting external venting done properly can be fun.