Difficulties with wearing a device? discussion

I’ve just realized that I fall between the standard ring sizes provided with most devices. At 50mm, my testicles tend to slide back depending on how I’m sitting or even while walking around. If I go for a 45mm size, it cuts off blood flow and makes me turn blue (which isn’t great). It seems hard to find websites that truly offer custom-made devices. Does anyone know of any good ones? Sometimes I miss them when searching. My preference is locks similar to those found on internal holy trainers, but I really like the feel of steel; it’s been the most comfortable option for me based on my experience using a CB.