Hi @Ben,
We have a post about 450mm quad assembling on this community forum. There is a list of all components as well. It was written for Navio+, however, it’s also relatable to Navio2.
If you doubt about battery size that you need, you can check its characteristics with the LiPo battery calculator. For example, with this.
Regarding motors and ESCs brands, I hardly can suggest something specific. However, some of our users may have a similar experience 