I am in the process of planning and purchasing parts for my first freezer conversion. I am using an upright freezer, internal dimensions are approx. 5'x2'x2'. I am mainly looking to use this smoker for temps under 170. I already have a digital controller for whatever element I get. I will be using 1 or 2 AMNPS for smoke generation. I am just wondering what size heating element I would need for this sized smoker. Thanks.