I know no chair is really BIFL, but I know some of them can last a very long time. I'm 6' 4" 200lbs (193cm, 91kg). I'm looking for a chair with a long seat pan. I'm not sure if I have long legs or this is just a preference thing, but I always feel like seat pans don't extend out toward my knees enough, I feel like they end too soon under my thighs. It seems like most chairs have a max seat depth of around 18.5".
I tried a Haworth Fern, but I can't get really comfortable in it and always feel like I'm going to fall forward out of it (exaggerating obviously, not sure exactly how to describe it) because the seat ends far back from my knees.
I prefer foam seats to mesh. I've sat in an Aeron, it won't work for me because I sometimes sit on my legs and can't do that with the hard edges around the seat.
It seems like my options are pretty limited. I found the SecretLab Titan XL which has a 19.7" seat depth, but this is a racing style seat (not ergonomic) and I've read they don't last very long. I also found the Oak Hollow Aloria which has a 22.25" seat depth, but I've never heard of this company before, going to look into it more.