Your first idea is doable, the second looks like a cold smoker. Variations of your ideas were in Mechanics Illustrated in the 50s and 60s and I'm sure many people built them. Your horizontal grill needs to be raised from the wood on bolts and the wood protected from heat by diffuser metal.
I think your UDS and horizontal grill need a third vertical UDS style barrel with an offset wood burning firebox(also a M.I. plan). I'm sure these plans have been posted by a Brethren within the past 3 years.
Your climate is similiar to mine and I need to wrap my UDS in the winter to keep it efficient. You would need alot of fire to melt the snow off two drums.