Is there really any reason to pic one of these 2 methods over the other?
first:  the gun rack like this: rack

or the hangin style racks like this: hanging

I was also thinking of using this old shoe hanger that went on my door that has individual pockets for shoes.  Maybe attach that to the door and cut to fit.  
Just looking for cheap and easy. going in an 18 gun safe and only have 5-6 hand guns now.

ive used both, the hanging style is not compatible for 22 calibers so I use the others for those. I only have one shelf in the safe and room to put the rack is limited so I try to hang.

Nope. Just depends on your setup and which fits your safe better. I use pockets on door and the racks on the top shelf. No room for the under shelf holders now.