I would say Dot Points and the Riley Workbook would be best because these are both written questions and have solutions, Checkpoints is just made up of HSC questions (sorted by topic and edited probably) useful, but HSC papers are available for free. I don't think you'd be able to do all of the questions from all of the books (which isn't advisable anyway) so investing in all of them doesn't sound like the strat lmao. They'll also probably have a lot of overlapping content/questions. Hope this helps
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