Assistance needed with girth and foreskin issues

Hello everyone, I signed up nearly a year ago but held back from asking questions. My wife and I wanted to give chastity play a shot, but since we weren’t sure if it was for us, we didn’t want to spend much on a custom device. We started with a standard knockoff CB6000 that was too small. Then we tried some metal cage—maybe called a birdcage? It was too large. I’m uncircumised and my foreskin causes plenty of trouble. My flaccid girth is about 5.5” and length around 4.7”. We bought another knockoff, something like a cobra with a slightly larger inner diameter, but I still can’t get it to fit. So the question is: since I’m too small for the birdcage (and my wife didn’t care for the look or feel of metal) and too big for the CB6000, what should we try next? How do we make it work without spending hundreds on a custom cage? Thanks in advance for your answers, and please excuse my English.