Set the Filter

Hi,

There is no need to create a brand category. There is already such general category in the menu Products>Brands. There, you can directly create your brands.
Then, in the "brand" setting of your products, you'll be able to select among them.
And you'll also be able to use brands in filters.
You can also use a custom product field yes.
The main difference is that with a brand, you can create a menu item to display the brands similarily to how you would do it for categories listings), while with a custom product field, you can display a listing of the values of a custom field, or add images/description, etc to each value.
And both can be imported to your website via CSV.
So it's rather a question of what you want to do with your brands, than what HikaShop can do in that respect.