Man, you're going to get alot of opinions on this one. When I bought my first reg, not that long ago, I remember being somewhat overwhelmed. I ended up buying the SP MK2/R190, due to it's price and reputation for bullet-proof reliability, as well as ease of service in many parts of the world. For recreational diving, almost any regulator from a reputable company will work fine. That's the good news. The bad news is that there's tons of hype and ferocious brand loyalty out there, so it's kind of difficult (to say the least) to separate fact from opinion.
Regarding service, there are plenty of places that will service regs bought from an online "non" dealer or a used reg. The price difference in warranty annual service between paying for parts and getting free parts is not that significant, as the parts replaced under routine service are usually cheap. So I wouldn't be afraid of buying something used or online, as long as you can get what you want.
The other thing is that high performance regs are really not necessary for enjoying recreational diving; it's kind of like buying an expensive sports car to drive around town when a honda or VW would do everything just fine. Even the modest SPMK2 delivers more than twice the air a diver will ever need at depths even close to recreational.
So, the choice is yours. Many people buy entry level SP or aqualung regs and love them; another popular choice is the zeagle envoy. Even though the reg is a VERY important piece of gear, you won't notice nearly the difference between any of the standard workhorses as you would between different types of BCs or wetsuits.