I'm also in your boat. I'm 194 and weigh 90kg. To get a suit long enough I'm usually looking at a XXL, XXXL or something that is so baggy you could probably fit in there with me.
Another thing to consider is a suit that comes in two pieces: separate tops and bottoms. These tend to have a fair bit of overlap so when you're taller you just have less overlap or may stuggle to get the shirt tucked into the leggings (if that matters). Look into freediving suits or some of the neoprene alternatives (Lavacore, sharkskin, 4th element thermocline, etc) you can usually get a bit more length that way.
Also, don't worry too much about it being a bit short in the lenght. I've done tons of dives in colder water (10-14C) with a 7mm wetsuit that wasn't long enough to overlap with my boots. I'd just end up with a band of red skin where the two didn't meet, but it never hurt or anything. And I wasn't too cold since the suit fit properly in the girth.
Another thing to consider is a suit that comes in two pieces: separate tops and bottoms. These tend to have a fair bit of overlap so when you're taller you just have less overlap or may stuggle to get the shirt tucked into the leggings (if that matters). Look into freediving suits or some of the neoprene alternatives (Lavacore, sharkskin, 4th element thermocline, etc) you can usually get a bit more length that way.
Also, don't worry too much about it being a bit short in the lenght. I've done tons of dives in colder water (10-14C) with a 7mm wetsuit that wasn't long enough to overlap with my boots. I'd just end up with a band of red skin where the two didn't meet, but it never hurt or anything. And I wasn't too cold since the suit fit properly in the girth.