As an item that can be found on the floor.
Yes, because they can be found on wild Pokemon, allowing you to get as many as you want.
Edit: Unfortunately, you can only get one of each on the ground. Sorry.
You can only get one lucky egg, from Courmine city, currently. If you can get another one I am unsure of how / where.
Mageneton are occasionally caught holding the Metal Coats, however I am again unsure of the frequency of it.