Yes, we offer custom armored steel security window shutters that are lockable from the inside. For budgetary purposes, we recommend using a steel door instead of adding steel shutters to a glass door.
Another option would be to design your container to have the door located behind the shipping container doors, so you can seal it up that way. However, we are a fully custom shop - so we can accommodate pretty much anything you are looking to accomplish.
 What type of containers do you use? Are they inspected?
   What type of containers do you use? Are they inspected? 
           What foundation options are available for shipping container homes?
   What foundation options are available for shipping container homes? 
           Can you help with permitting, if necessary?
   Can you help with permitting, if necessary? 
           What is the insulation like? How do they perform in extreme heat or cold?
   What is the insulation like? How do they perform in extreme heat or cold?