I wouldn't recommend anything smaller for a caique... with how active caiques are, the more room the merrier!
I have the HQ version of that cage (two doors instead of one) that I originally bought (second hand, intended for sugar gliders, but never used) for my cherry headed conure (RIP), then used for my cockatiels and bourke.
The tiels and bourke have since been upgraded to an A&E (really wish it was the HQ!) Double Flight Cage (never did like keeping them all in one small cage), and now the HQ cage sits mostly empty next to the Double Flight. It works great as a "holding cage" for Charlie, so I can take his cage outside and hose it down. With the double flight, I clean the cage with the birds inside. They don't really like it, especially since most aren't tame, but it would be a bigger pain to take it apart to take it outside to clean.
I've actually contemplated putting the single and double flight cages together, but I honestly don't have the room for that! At least, not in the way I'm imagining... and it would look rather odd, since the single cage is black and the double is sandstone.