[cypher]

Your ham does sound like a lovely guy & I agree that the hamster heaven is a nice cage but that's (or a similar size & style of cage) is what I keep my Russian & Chinese hamsters in, the ovo most definitely isn't suitable for any hamster in my opinion, it does seem a shame having bought it not to use it but dwarf hamsters need a similar space to syrians just slightly different toys, layout etc.

Of all the dwarf species I would say the Russians, either WW, Campbell's or hybrids, are the easiest to handle, although fast they aren't as fast as Chinese or Robos, they are generally easy to tame too, Chinese can take a little longer often being a bit skittish & shy to begin with although they do tame well & make lovely pets. Robos being super small & super fast are probably the hardest to handle, how easy they are to tame seems to vary quite a lot but not the easiest.

No species needs to live in pairs & it is really quite unnatural for them, most pairs end up falling out as they mature & need to be separated, all species will live alone very happily.

General care isn't very different really, with some species, Campbell's, Russian hybrids & Chinese you do need to be aware of the potential for diabetes & take extra care with diet.
They can have smaller houses & wheels, not too small though (mine have 9" wheels) & smaller toys, they generally like lots of small hideouts & a sand bath is much more of an essential with dwarf hams than with syrians but otherwise care is very similar.