Any training in leather cleaning is a must. Just like carpet cleaning it is wise to do a course. As to which company ? then location usually dictates.
For the guys coming in April, it would be wise to have some knowledge of leather cleaning and repair first, for you to fully take it in.
As regards to getting work for leather, its the same as carpet cleaning,if you advertise it you will get it.
I normally get between 4 and 10 leather jobs a month.