Guidance on the Holy Trainer V4

Hi everyone, apologies I joined this forum a year ago and have been trying chastity on and off for the last year. Sorry for taking such a long time to post again. My husband doesn’t mind it, but isn’t overly keen on it while still supporting me in trying it. Recently we have started fresh with a DD life and I want to incorporate chastity into it. I tried some of the Chinese metal cages and a knock off set of Holy trainers as suggested by helpful members of this group. I have settled with the Holy Trainer knock off well. However, I am still struggling to sleep in it. Last night I managed to keep it on until 0530 in morning which is real progress for me. Thinking seriously about investing in an official Holy Trainer V4. Just a couple of questions How on earth do I decide on cage size as there are so many. I think I have standard in the knock off at the mo but there is a gap at top when I am at my smallest, however it’s not the easiest to get on to begin with! I am uncut so I would worry about my foreskin being an issue in smaller sizes. Will I find it more comfortable than the knock off for sleeping in or is this really just taking time to get used to it? I find the ring the most annoying thing tbh as the feeling of it touching my legs just seems to keep me up. I prefer to sleep on my back, so I don’t think this helps. Thanks for any help in Advance!:)