I would stay away from the SR-1, that thing is over engineered, too many parts and pieces. There are way to many good proven designs around to bother with it. I am a fan of the older Sherwoods, they are not super performers but solid dependable regs, high on my "if stranded on a desert island" list but the SR-1 is at the bottom of all my list. A mid range reg from most any of the major makers is fine. Don't bother with the top of the line models, 99% of the extra cost is pretty rings, cool colors and bragging rights- "I got the top of the line", the guts and performance -what really matters- are exactly the same. I would suggest you avoid lesser known brands, not because there is anything wrong with them but rather because service can be hard to find or in the case of newer brands, they may not be around long. For dependable parts availibility and ease of finding service over the years and the world, Scubapro and Aqualung are hard to beat.
I would also caution you on buying form eBay. Most all of those regs are not under warranty- reguardless of what the add may say and you never know what condition the reg will actually be in when you get it. In any case, plan on adding another $100 to $200 for service when you get it, that is the only way for you to know for sure what condition it is really in. A much better place for used regs (and I like used regs) is a local seller - Craigslist is a good place to look- that way you can get your hands on the reg and inspect it before handing over the cash.
