To put it another way, picking the cam based on the sound at idle is not the right approach if you're wanting good power. You need to pick your parts based on your 91 octane fuel, and once you have your static & dynamic compression ratios set, along with proper squish pick the cam for optimum performance across the load range and let the idle take care of itself. Having an engine built by a reputable shop is a good idea, and I also believe that buying a complete engine from a reputable supplier like Chevrolet Performance, or even SummitRacing or JEGS is a good approach for you, too. You'll be time and money ahead over trying to build the engine yourself, even considering shipping cost and import duties, I expect. With a complete engine you'll get a nice warranty, too.