Hello!
The Hendersons Reading Comprehension course is really good, in my opinion.
I mean, it shows you how to absorb the key details from seemingly-worthless sentences and other key tips that are important for the selective school, especially because the texts are long and you need to be able to scan for important details.
Since you already go to math tutoring, you don't need to worry about the Hendersons Math Course.
For verbal reasoning, they basically tell you how to go about doing different types of questions. For example, they have big lists of root words, suffixes and prefixes that will be very useful in the exam. Instead of memorising all the vocabulary words, it would be way easier to understand the roots, suffixes and prefixes so that you can easily figure out the meaning of words. Although, then again you can get lists of root words and such from online.
Since you have ATARNotes for writing, you don't need to worry about that.
For numerical reasoning, they give you ways and tips to figure out specific patterns or solve word problems.
Overall, Reading Comprehension and the essay feedback they gave was the most beneficial for me!
I hope this helped and if you have questions, feel free to ask!