Best device for me? - classic cages don't work so well

Hey cucks and mistresses,
as someone who wants to take chastity 24/7 seriously from now on, I need advice on which device to buy.

I tried classic plastic and steel. The CB6000 stuff is much too small for me. My latest purchase was this one: http://www.amazon.de/gp/product/B00WDE3ZGM?ref_=pe_386171_37038021_TE_3p_dp_1

At least I fit in it but it's still nowhere near a perfect fit. It's still somewhat too small in length and diameter and the base ring slips pretty far forward down the shaft, although it's already rather tight and I can feel it decreasing the bloodflow.
In short: These classic cock cages just don't seem to work too well for me. My penis is about 10-12cm flaccid and about 19cm when excited which makes it difficult to find a fitting cage. Also, it's kinda thicker at the base than at the top, so every base ring I tried just gets pushed down the shaft. I can pull out pretty easily aswell which makes the keys dangling from her necklace somewhat less attractive.

That's the story so far. Now I tried the cage I linked above for a few days now and although I can't wear it 24/7, it's a nice experience to be locked. I want more of that. I want it to be the rule and not the exception.

The question is: Full belt or PA Piercing? Or are there other options?


PS: Today we're visiting my gf's family while I will be locked in my current device. Maybe some latex underneath and a plug for me, how does that sound?