There are several considerations when choosing enclosures, most of them already shared, but let me add and summarize:
1) Can you hold the Humidity level you need for the mantis in the enclosure?
2) Can you hold the needed Temperature in the enclosure?
3) Can the Mantids find the food (or the food find the mantids)?
4) Is there enough room for the mantid to molt in?
5) Do the mantids need furnishings like branches, leaves?
6) What do you want the enclosure to look like for visual appeal.
7) How much will it cost to accomplish the set up you desire?
8) How much will the
on-going cost be in heating the enclosure?
9) How much work do you want to do to clean the enclosure?
All that being said, Ghosts with houseflies or Blue bottle flies as a food source would work in any size container, as the food will land near them, unlike ground crawling food. As practical as all the smaller plastic containers are for cleaning and food sources being close to the mantis, if you enjoy having a decorated large enclosure, I would suggest you build what you want,and enjoy it!
CHEERS!!! :
Nick Barta