I use this one:
http://www.nesco.com/products/?category=300&subcat=100&id=36I've added 2 trays for a total of 6. 6 trays will fill a gallon ziplock with jerky, which is about my batch size. I run it for 5-5 1/2 hours depending on which recipe I use (the thicker the marinade, the longer the dry time). I'll have to check, but I think it's set on 135 degrees.
The secret to jerky isn't the dehydrator, and it's not the marinade either, it's the slicer. Making your own jerky is time prohibitive if you have to cut the meat by hand. I've got an older slicer that I'm sure they don't make anymore, but the style is still around. It's a rotating blade like the kind you see in sandwich shops. All stainless steel and the motor comes off so the rest can go in the dishwasher.
I've found jerky to be a great way to get rid of ducks and geese, and each of the last 2 years I've made a whole deer into jerky. It's easy to give away, take to parties, or munch on in the field. I've even sent some to soldiers in Iraq.