KitchenAid is really strong and durable. Expensive though but other’s that are good: Breville, Kenwood K, Cuisinart. Make sure you get a sturdy one made of metal (preferably)(no plastic) and get a metal or glass bowl.
If you haven’t already decided on a stand mixer brand I thought I’d give you some food for thought. I have a both the Breville and a KitchenAid semi-pro. I LOVE my Breville. Its wonderful for smaller, lighter jobs – ones that use between 500-750g of flour though I’d stick to the low end of that range. If it were a little bigger I would call it the perfect machine though I imagine not everyone wants to make their own granola bars. I make this heavy, sticky batter often so I opted for a KitchenAid semi-pro model. It does the job with the heavy batter better but the rest of it isn’t nearly as efficient, for example, using the dough hook bread doughs don’t come together as easily and quickly and I have to stop and scrape the bowl at least twice to help the machine along. Unlike the Breville attachments, however, all the KitchenAid ones are dishwasher safe. Hope this helps.