Circulation fan placement

[sledhead01]

I have had my 6 rack digital for a year now and an very happy with it.  I am upgrading to a 750 watt heater into it as I want to stick with the original digital control box.  I would like to add 1 or 2 circulation fans into it to help move the air around and even temps out so I do not have to move racks as much.  I often double up my racks to 12 when I am doing jerky.

I was thinking of just using convection oven fans. Not a squirrel cage fan like Beefmann did.
What is the best fan location for circulating air?  Down by the heating element, up near the top???
Just looking for some other opinions or suggestions.

[beefmann]

considering the height of the 6  rack,,, i would do one near the heater,, and one 2/3 or 3/4 the  way  up ,., room permitting