Thanks again for all the replies guys. Im pretty happy that i posted this and you guys showed pics of what the 100-400 can do on a crop sensor. Like i said my first plan was to get the zoom lens but when i read a few reviews they were all saying the prime was way better. A zoom will be much more versatile for me so thats the way im gonna go. Thanks to all that answered you have helped a lot !
Happy New Year every one.