It depends On what your willing to spend etc. the jbl ones are good, but you pay more, same with any top branded regs but you pay for what you get. To be honest though some of the eBay ones are just as good. I'm selling one in the for sake section at present, and that was just short of 60 with delivery and worked perfect.
They all do pretty much the same thing, however some regs are working pressure adjustable, so if you wanted a diffuser that requires high pressure then they are your best bet. Combined regs save you having to go to more expense to purchase a Seperate regulator too.
You have regs by tmc, azoo, up, jbl etc. it's down to personal choice and practicality.