Metal devices most similar to the HTV3

Has anyone found a metal cage similar to the Holy Trainer V3? The size and shape of the ring, the gap between the ring and the cage, the locking mechanism, the downward orientation, the stealthiness, and the comfort of the HTV3 is really hard to beat. I would like to get a metal cage, but due to the cost of a custom design, I'm really hesitant about spending the money on something that isn't as comfortable and stealthy as the HTV3. Any thoughts or comments would be most appreciated. Thanks.