I'm sorry to hear about your dragon. Are you looking for something to handle or just watch? Lizard or snake?
You could look at something like a colony of anoles, or turn the 55 on end and make an interesting vertical tank for a crested gecko.
I love hognose snakes to pieces, a 40 is probably too big for a baby, but a larger female might like it if you landscape it well. Garter snakes are also interesting, and the big tank could be made into an interesting pauldarium for a garter.
They are similar too but still different from bearded, but you could also look at Rankins dragons.