After some initial adjusting and 'fiddling' with my Halcyon rig, I got all the bugs worked out and it IS great!
Go with Halcyon and get their backplate (BP), Wings, Harness, Bolt Snaps, and DIR 5 ft or 7 ft LP hoses and one 22" LP hose. GREAT rig! Modular, simple, reliable, will grow with you, streamlined and like zero drag in the water, secure, no bulk in front of you, etc.
Halcyon = Quality Tech gear, be it for cave, wreck or deep diving..