Found this site by looking up a Cherry Keeper review. I think this is a good resource for those into male chastity. I'm subscribed to a few subreddits for chastity and male chastity, another resource can't hurt IMO. Anyhow, I'm almost 40 and key holder to my bf (44). We've been doing this off and on since November 2018. We've had some difficulty finding the right cage for him. Right now we've got him in one we cobbled together, silicone cage with a plastic ring. It works, but we'd like something better. We tried getting a stainless steel cage, and the same size ring we've gotten for plastic was too big in it! It literally fell off, not to mention it was quite heavy. We're definitely interested in the Cherry Keeper, especially after reading the review on here.
If plastic is what you are looking for then the Holy Trainer is a good choice as it is very light and well built. It sounds to me like you are using too big of a base ring. Try testing with some of the cheap chinese cages you can get of Ebay for $10-20. If you are looking for full custom Steel and Light weight, then Mark at Malechastitynow.com is a good place to look. His turnaround time is very quick and his cages are very comfortable. Check out my pics and you will see. Welcome to the fun.
We've been trying the cheap ones on Amazon and eBay. The plastic cage is hard to keep clean, the silicone ring pinched him and broke the skin. We have considered the Holy Trainer. We like what we've read about the Cherry Keeper because it can be a custom order if needed, it's lightweight, inexpensive, and easy to keep clean. It's 3D printed plastic. I just looked up that website, way out of our price range. Thanks anyhow!
Welcome to cm! I am with @Shepherdsflock stainless is the way to go . Custom made . They may be pricey but well worth the investment
We've found success experimenting with different inexpensive steel ones and we found one that fits and works 24/7.
Welcome here, sounds like you're going to fit right in. I have no advice but feel that I shall learn much from both of you!