Is there an problem of interaction with Pressure Treated wood and steel siding? I have read about PT and aluminum, but don't see anything about it with steel. Long story to follow:

I am in the middle of restoring our used-to-be-enclosed porch to the original open porch with craftsman styled low wall around the edges. Prior to our ownership of this home it was completely encased in steel siding that unfortunately is in too good of a shape to justify its removal, but as you can tell, it is not exactly my favorite item, and if it ever fails, the house will be redone in Hardie Plank or some such similar. As I peel back parts of the encloesd porch, I will have portions where the steel siding from the "outside" will abut the wood trim on the "inside" of the porch. What wood is bettter to use in this case? PT or cedar? None of the wood is coming in contact with the ground and will be under the roofline. Would it be simpler to use cedar and avoid any potential interaction? I plan on staining/paining the wood eventually.