Hi Matt,
that's a tall order. OC is certainly the simplest, the advantages of a rebreather are gas preservation and with a CCR a deco advantage. RBs also offer moist warm gas, reducing the bodies workload to keep temps up, reducing dehydration some and give more comfort (no dry mouth).
That comes at the price of additional unit components, additional maintainance and pre-/post-dive checks, increased chances of hypercapnia, hypoxia and hyperoxia. More components to fail, but also more options when they do. Expense for the unit itself and training, plus supplies and upkeep. Some of that will be offset by savings in gas, so financial feasability depends on the amount and types of dives. The amount of OC bailout will stay the same.
You need to analyze your needs and wants and find a matching unit, covering those as close as possible. Size and weight as well as features differ quite a lot in different models. Some are fairly small and light (less than 50 lbs) and rated for many hours. Exploration type units can weight in excess of 70 lbs but offer many more features.
If you follow the link in my signature you'll find a webste that has wide array of articles, covering everthing from the small, inexpensive, manually controlled Sport Kiss to the large, expensive electronically controlled Cis-Lunar and Ouroboros. As well as plenty of articles that deal with a variety of subjects concerning rebreathers.
Another consideration is that you'll have to start from scratch, as plenty of new skills have to be learned and old skills relearned. It'll take you a while to get back to the level of diving you have on OC.
