Kaplan vs. Khan Academy for MCAT

So, I’ve been trying to finalize my sources to use for studying the MCAT and with all companies carrying preperation it’s quite hard to find one that is the best to prepare you. The most talked about from what I am seeing is Kaplan and Khan Academy, but I’m unsure as to which one out of the two is the best source. General question for anyone going into medicine or even those who have already gone through this, what is the best source?! I’ve also been looking on amazon for the books and noticed that kaplan has 7 books and it’s the third edition. So, does edition matter? if so which edition is best? Are there only 7 books total?