The Aoharu suit would look perfect on you, I myself used to have a larger avatar and it always looked great
"in the past with styles similar to those shown in your pics and, for whatever reason, there's something which never seems to look quite right."
THIS is the exact reason I made away with my big muscly look and went and got a smaller more versatile avatar. Having those big avatars will ALWAYS limit what you can wear. For me my style is predominantly urban, so baggy pants, baggy shirts, big sneakers, piercings etc etc but this didn't work on my big avatar, it just never looked right. Too tall and too big.
If you REALLY want to explore the styles SL has to offer in my honest opinion you will need to downsize your avatar to pull it off.
The shoes I'm weaing in the pic are from a store on the same sim as Aoharu called Anexx. Their are Horse-bit Loafers and are also sold in the store next to the suit