Alton Brown gimmicked up a smoke rig on one of his shows utilizing a hot plate coil. You should be able to find information on that on FOODTV.com.
I, too, would worry though about concentrating that much heat inside an insulated unit such as Masterbuilt.
Alton's was pretty UN-insulated as I recall. Clay pots and such.
I might consider taking the $100 and trading up to something more reliable. Just my 2 cents.