O Three are amazing quality, all commercial diving in the fish farms or underwater welding industry here in Ireland and U.K. use O Three, fully custom made, compressed neoprene drysuit.
Another one to research would be Ursuit. Not many have heard of this company. I went to a dive show in Ireland and met one of the managers of Ursuit, he was very friendly, gave me a lot of helpful info. Have not used one myself but anyone who has used any Fourth Element Drysuit, has used an Ursuit drysuit, as Ursuit in fact make the fourth element argonaut. They are Finnish made, fully customisable (you can add wrist seals, pockets(where, how big), and anything else. I have seen these suits in person and they are top notch quality, and actually they use better material in their suits than fourth element's argonaut drysuit (more durable and more flexibility)