I bought my 105 used on ebay, and it doesn't have the fans but I think that is the way to go. I open the door about an inch off and on and it is acceptable but not the control I would like to have. Before I used to do jerky in a small commercial dehydrator and it worked fine except for the lack of real smoke.
It will probably take some testing etc. but a 250 would be the way I would choose if I had the facility outlet to make it work. With a few free samples I think you might have to keep it running full time. I'm almost in that mode now.
Jerry