Good devices for larger men (long-term)

Having tried a rikers device, I found it impossible to wear for longer than a few hours. The largest ring it came with fit fine, but the problem was the tube was way to tight, making it very hard to even get it on. My research shows the CB Curve or similar style cages are more for larger men. I also was curious on opinions for metal or plastic/silicone for long term wear?
Any help or advice would be appreciated.