All those fans will interact with each other.
First priority is allways air in the front.
Whichever arrangement you use will have a negative effect, but I would go for this type of stuff to make it.
http://www.screwfix.com/app/sfd/cat/...01310&ts=05716
Overclockers is a good place to start:
http://www.overclockers.com/articles1256/