after i got an Amoresy catsuit, i couldn't go back to leggings of any kind, the feeling of having your whole body covered was literally 50% more satisfying than just having your lower body in spandex (at least for me anyway)
so my personal suggestion would be to forget about leggings altogether and only go for body suits
the rationale simply being, the more coverage the more satisfying
i actually threw away my entire collection of leggings/tights after i wore the Amoresy catsuit because i knew i wouldn't be going back to leggings
it's like toast vs toast + butter, after you've tried toast + butter, you'll never go back to simply eating a piece of toast on its own
well, that's my opinion and preference anyway
as for which suit, if you can reach one arm over your shoulder, and the other arm under, and make your finger tips touch behind your back, then i believe you can work the back zipper
if not, then yes, the front zipper would be more fitting
so the Athena suit for back zipper, or Celestia for front zipper
regarding size, there are two points on your body that can stress the zipper as you put the suit on
#1 hips
#2 shoulders
if you think you have wider hips and/or shoulders than average for a man of your height, then i'd suggest ordering one size larger than the suit recommended based on their height chart (others have even recommended buying 2 sizes larger)
if you have narrow hips and/or shoulders, then i think following their chart recommendation is fine
i made the mistake of ordering one size smaller, and honestly, it feels like the zipper might break every time i put the suit on
the main point of concern is shoulder width, imo that has little to do with body fat %, and more to do with bone structure