STARDIVER

I am currently somewhere between a sport diver, and a wannabee tech diver. I am a rescue and recovery diver for my county, and get lots of exposure to austere conditions. I have done some deco, and have most recreational specialties under my belt, as well as several hundred dives, ranging from 30 foot warm water to 120 foot ice dives. I have decided to get trained on and purchase a CCR in order to access some of the great deep wrecks. I wish to understand the differences between the CCR units available, and choose the one best suited to my mission. If you have any comparative remarks on the units available, specifically the models best suited for long deep dives, I am VERY interested. Thanks!