Hiya,
if they have been together for a while, then they could be ok with no problems, but they could start fighting or squabbling once you rehome them, once they get a new cage, new toys etc. - it is going to be weird for them to have to re-establish territories and hierachy, etc. but, saying that, some Robos have to go through that many times when they get cleaned out, moved to different cages etc.
I would say that if you are prepared to have split them up if you need to, with two spare cages and spare accessories too then go for it - you can only try them and see how they get on - just keep a close eye on them and be prepared to split them if necessary.
If you dont think you have the resources, or space for more cages, then just get the one singleton, or even both singletons
- if you have the space for two cages
It is completely up to you and depends on your circumstances
Tammy x