Hey manza -
I was in your shoes about two years ago. I started with a generic regulator at first and I had problems with it every so often. Green Leaf Aquariums have some very well build regulators. I took the plunge with their Ultimate II CO2 Regulator. It's pricey but it's solid, well built, and no end of tank dump (I have had my co2 tank run empty a couple of times). And the warranty is pretty good. Don't skimp on a regulator that can eventually malfunction and kill your livestock. Good Luck in your quest!