Joe, I truly find the birchbark call and my voice to be the best. A made birchbark call will run you like 10-15 bucks canadian most. Being 100% frank it is not real hard to mimic a moose either bull grunts or cow calling, remember you have all summer to learn and practice. The cow call if I were to describe the sound is like a domestic beef cow but nasally and instead of a mmm an errr sound to begin with. The can and shoe string method is also easy but lacks some IMO. I suggest you try to find a calling moose vid or tape, the other option is try typing in Moose calls into a search engine....you should finds some wav file examples on the net. Once you hear some you'll see what I/we mean.