I have found that often even day geckos of the same species don't do well together, so I recommend either getting several small geckos of the same species (I'd recommend all females) or sticking to 1 gecko. It's possible that in a large enclosure like that with lots of hiding spaces the same species geckos won't bother each other, but there's still no guarantee. I've successfully kept a number of geckos of the same species together in small groups including leopard geckos, crested geckos, gargoyle geckos, but the one time I had 2 gold dust day geckos together (both female, though my enclosure size I think was too small) I ended up with only 1 gecko eventually.
Aliza