I knew this would draw your attention
Just outside shoulder width, i.e. replicating the same grip I use for bench.
/edit - Oh and with a lean back, not quite gironda style. Perhaps this helps the shoulders somewhat, as it feels better than when you are trying to stay completely upright.
I start from a dead stop and do them in a controlled fashion, feeling the muscles in the back. If it doesn't make me wider, then it must have been stopping lat pulldowns because nothing else in my program changed :O