I scored 1000+ on my exit HESI last month on the first try. My school requires a 900 as well. I can tell you how I studied.
To let you you know....you are right...the HESI questions are much different from NCLEX questions. So here is a "mini" explanation of how I studied:
1. I used a website called hesistudy.com. It's not a scam as I saw listed on another post. It helped me immensely because it has questions that are VERY similar to the style you see on the actual HESI. There are 100's of questions there. It gives thorough rationale, and there is also a study plan available.
2. I brushed up on CONTENT (pedi, OB, etc) through Saunders and NCLEX 4000. I made sure to read the rationales. The questions I missed I wrote out the rationale so I could go back and review it later. *OB was my worse subject before studying this way...I scored over 1500 on OB on the actual HESI*
3. I purchased the Evolve Hesi book...used it to also brush up with content.
If you have any questions feel free to ask!