Suggestions for storing homemade frozen custard
Any air tight plastic container will do to keep smells out. I use either cheap, disposable plastic leftover containers, or used ice cream tubs that I saved from previous purchased ice cream.

As for the crystallization- The only way to prevent that is my having no air in contact with the ice cream at all. I don't know how to solve that completely. I avoid the issue by not making more than we can eat in a reasonable amount of time (a week or so).