No cage will ruin your penis. The only way that can happen is if you're a sissy-trap and you decide to go full girl mode and you want to turn your penis into a clitty, which means being in near permanent chastity(that still won't fuck you up) AND doing HRT (which will ruin your penis). Not even the guys that are locked up the entire year, and only allowed between 6-12 erections and orgasms a year don't get ED from being locked in chastity.
I think the cb6000 and cb6000s are the best for a first chastity cage because they come with all 4 rings and space sizes so you can keep changing it until you get a perfect fit that keeps you from getting an erection, but isn't uncomfortable when not aroused. They're around 150$
I absolutely LOVE my Birdlocked (I'm locked in a mini currently because despite being 7-8" erect depending on the day and the fetish my gf is indulging, I'm less than 2" soft so I need a tiny cage. This device is incredibly comfy, it costs around 130$ BUT you better have your measurements right when you order because the parts aren't modular like the cb6000.
The Holy Trainer 2 is probably the best non-custom made lightweight steel device you can buy. But, getting the cage, the awesome internal lock made for the HT, and maybe an anti-pullout, or escape attempt punishment device, you're looking at around 200$. It's the next device I'm buying(i own a cb6000s and a Birdlocked Mini) but I heard the HT2 is the most comfy and secure device right now, and that lock is just too cool.www.keptforher.com/
free shipping when you order a cage package, discrete packaging and billing if you need privacy, great customer service, and their site is full of great sizing guides for finding a chastity device to fit you.
I hope this helps out.>here's that cool lock that I'm sure some of the guys locked in an HT2 here will say is awesome.>pic is a birdlocked guy teased by his sexy beachgirl with the chastity cage key on her barefoot anklet