Novices and newbies discussion

I own a knock-off CB-6000 as my first chastity belt, but I found it quite uncomfortable and am looking for something more comfortable. The HTv3 seems to be the top contender (and yes, I prefer getting the authentic version). However, I’m unsure about which size to choose. My penis measures around 6.8 cm to 7 cm depending on how you measure. Should I go with the standard HTv3 or the Maxi? For the ring, I followed the sizing method taught by HT on their website and got a result of 45 mm, which matches the diameter I used in my old CB. I believe it won’t cut off blood flow, though I’m not entirely sure if it’s tight enough to prevent the ball from slipping out. Lastly, besides HT, are there other brands worth considering? I plan to stay locked for up to a month if my girlfriend isn’t around; personally, I really want to try that duration since 1 week has been my longest attempt so far (I got eczema with my old knock-off CB-6000).