Hi Alice, if you are not going to build a background and work mostly on the ground, you could go with D. Tinctorius, a pair of Azureus for example. Or Dendrobates Leucomelas (leucs) who do really well in groups, and are a great starter dart frogs. Stunning, too. These frogs are terrestrial by nature and will enjoy all the space your viv will have. And they are bold, too.