I'm now trying to find a terrarium large enough to house C. parsonii.
I've heard of Parsons being kept in 4 by 4 by 2 foot terrariums and seemed to be doing fine. Although with Parsons you can never have a cage that is to big. Could not say how big the Parsons that were being kept in those Terrariums though I think they were mostly temporary or grow out terrariums and not for adult Parsons.
I'm working on a larger terrarium as a sun terrarium for my male Parson.
Since you are in California, I would considering contacting Jason at Protean Terrarium if you're looking for a large, custom terrarium. I had some smaller models built by him which can be seen in the enclosures thread. The prices are extremely fair, and you likely would not have to worry about shipping due to your location. Don't want to seem like a shill, but I don't know anywhere else to get the same type of work for their prices.