This forum is much more freindly than that "other" forum Robin. You are going to like it here. I have been "lurking" on both forums for months.
By the way, I am copying your great idea with using the oval cattle trough as a base and building up from that. The finished cage will be 3 1/2 ft deep, 8 ft long, 6 ft tall. The trough is completely filled up with a mix of dirt, mulch, and a 1 1/2 ft by 6 ft hollowed out tree trunk stuck in diagonally. I'm starting to build the top half. Thank you for the inspiration.
I hope you decide to breed Tegus Robin, it will be good for all to have another major player in the biz. I have 3 sub adult reds, 30-36 inches long. Great lizards!
Malone out.