A solid sided cage or an aquarium would be the most suitable choice of housing as they are small enough to squeeze through the bars of most wire hamster cages. (yourpethamster.com)
Dwarf hamsters and Roborovski hamsters being smaller in size don't do well in conventional wire hamster cages as they can squeeze through the wire bars, often with tragic results. (hamstercagesdepot.com)
For a discussion of the wire bars themselves and their pluses and minuses read The Good And The Bad About Wire Hamster Cages. (choosehamstercages.com)