I used to keep them separate, but if you give them enough space and keep a close eye on them you can keep them together. To me it seemed much easier to keep them separate other than for mating. You can more easily make sure each one is eating enough and you know you won't have issues with the males harassing the females too much. If there are any issues you'll need a spare enclosure anyway, so I figure I might as well have it and use it rather than have it and not use it. But whatever suits you and makes you happy is fine.
Don't keep males together. Pairs or 1.2/1.3 groups should be okay.