Good books for Orange level 6

[promotion]

DS has been assessed at 6, he finds the Oxford reading tree stories ok, but keen to add stuff we can read at home in addition

Have I understood the Usborne levels right if I order this set

Usborne My Second Reading Library 50 Books Set Collection Pack Early Level 3 and 4 and Young Reading series One amzn.eu/d/iLKmT9n

As something we can work through at home that won't derail the reading scheme work?

Or, any other suggestions please? He loves non fiction

When DD was at that level, she would pick up anything that appealed in the library and open and see if looked suitable. If seemed like she would enjoy it, we took it home. Some needed a bit more help from us but I preferred she was actively selecting what appealed to her

Yes, do make use of your local library. Don't worry too much about level if you're going to be reading them with him - you can help out with the words he can't manage. What matters most is the enjoyment.