Having been in a same situation and passing the EE FE recently, I would recommend getting the EE-Orientated review manual from PPI. As a supplement there are some review problem books on Amazon. The one I bought was geared towards the new computer based exam Review Problems Book.
The material you need to know is on the NCEES. There you ca find the break down of materials you need to know. Good luck!
As I am prepping to take the exam, I know PPI has an electrical specific one formatted for the new testing format (CBT). Also, I recommend "Study Guide for Fundamentals of Engineering ((FE) Electrical & Computer CBT Exam" by Wasim Asghar
This book is helpful for practice and it also tells you with each problem set where to find the equations in the reference manual - which will help you learn what to search for in the digital version come exam time.