I personally like the idea of having either puma or maned wolves in the exhibit. Although I too will add my (wasted) wishes to the list of ever seeing giant armadillos in a European zoo!! :')
I don't think the maned wolves would be a bad choice. I don't know if they'd be a likely choice of course, but the scope and space is certainly there. I am in agreement also that the indoor area of SotJ needs a bit more livening up. With the sloths soon to be circulating between indoors and outdoors, and the ants and tank not as eye popping as a random visitor might have hoped, perhaps some birds (eg sunbittern, Montserrat oriole etc) would do the trick flying around in there.
I dunno. I wouldn't mind seeing maned wolves over pumas, though I am ashamed to admit I have never seen a puma in captivity (it's the only 'big' cat species I haven't seen, I've seen lion, tiger, leopard, jaguar, snow leopard, cheetah, Indochinese clouded leopard and Bornean clouded leopard, in a rescue centre in Borneo, and it bugs me) so they would be cool to see.