There's kind of two main styles of boot bags. More traditional ones, and more backpack style boot bags.
The traditional styles tend to have a little more space if you're looking to haul everything at once, though Dakine does make a 75 liter backpack style bag that's plenty roomy. If you're looking for a more traditional style, the Kulkea bags are a nice choice.
https://www.evo.com/shop/ski/ski-bags/ski-boot-bags