Just be careful with those shutters. They are VERY easy to break. Actually received one with a couple broken shutters. The good news is that they are very easy to replace and Apollo was awesome about sending me out replacements.
I am in the same spot you are right now with just two. Working on adding more, but in the mean time, I cut custom foam to fit into the box to make sure nothing beats it up. If you troll on E-bay they have custom cases as well they you could mount casters to if you are looking for a cheap fix to last you a year.
Isn't it wonderful when you look back at these things 5 years later and laugh at how the fix was a temporary solution?