I would recommend something like these
http://www.ebay.com/itm/400247803189...84.m1438.l2649
They offer rather good general protection for your steels
Not sure if you need 200 though
But always nice to have spares
Then I would recommend a very very good carboard box
I personally keep some in a strong cardboard box and have one bottom layer than a thin layer of cardboard then a second layer of steelbooks and I find that works very well