Dear Zaf88
As a rebreather instructor trainer, I was a bit concerned that you want to find a used rebreather. Have you completed a training course, if not please complete one before you purchase.
You say you have 100 logged dives, have you certified in the use of Nitrox, if you havent you need to and get some EAX dives under your belt, as this will give you some underpinning knowledge as to what rebreathers are about.
How deep have you dived or what type of diving do you do. If you only stick to the 30 to 40 metre range your best option would be a SCR nice and simple to use, and will give you a start in rebreather diving. THe Drager Ray is a nice unit, easy to use
not to expensive, inexpensive to run, and if it goes wrong relatively inexpensive to have repaired
If you are planning on extended range or gas dives a CCR would be your best option, bear in mind however the purchase cost of these units is high, running costs compared to OC Scuba are low, but when they go wrong, there are no user servicable parts and repair and maintenance costs an arm and a leg.
Also beware, there are a lot of rebreathers out there, which are now obsolete, the manufacturer has ceased trading, or ceased manufacturing the unit. For your wallets sake get some specialist advice before parting with your hard earned cash
I see you live across the pond in New York. If you need advice on courses or which rebreather is worth buying, Try contacting
American Nitrox Divers INternational, Freeport, Long Island
516 546 2026. They will help
I hope this helps, but please do yourself a big favour and get certified before you buy. Rebreathers are a totally different animal to OC Scuba, and will bite you if you are not prepared.
Tim "gaschef" Stevens
ANDI Instructor Trainer IT#30