Hi Tali and welcome to the Disney Parks Moms Panel.
This is a great question and in order to provide you with as much information as possible, I am going to point you in the direction of a great series of Walt Disney World Attraction Vehicles and Seating Guides written by my fellow Moms Panelist, Erin F, for the unofficial website www.touringplans.com.
You can find the Guide for the
Magic Kingdom Park by searching for the following:- http://blog.touringplans.com/2014/09/23/walt-disney-world-attraction-vehicles-seating-faq-part-one-magic-kingdom/
Similar guides are also available for Epcot, Disney's Hollywood Studios & Disney's Animal Kingdom Theme Park.
These guides provide lots of really useful information including seating capacity per row, seating capacity per vehicle & height requirement for each and every attraction at all 4 of the Disney Theme Parks.
Although the guides were written back in late 2014, the vast majority of information is still correct. Please do note however that any new attractions added since that date will not be included and similarly, any attractions which have closed since that date will still be included.
Wishing you a magical trip filled with memories which will last a lifetime!
Emma