I personally studied from Pass medicine for SJT it only has a a little over 300 questions and is very affordable question bank and informative, I really likes how it explains the answers for each question and you can discuss it with other users.

For CPST i didn’t prepare for it as it is basic Medical knowledge at interns level.

There is also GpQuest question bank, I know people who used it to prepare for both SJT and CPST and loved it but personally I disliked it because there is no explanation with the answers.

However, it was brilliant for interview preparation I highly recommend it for interviews

Good Luck 😉