I have a curved-shaft rebuilt Echo. I bought it because I was really low on cash at the time, and to its credit it has been pretty reliable, but if you are tall I definitely wouldn't advise it because I'm 6'1" and I can't always stand up straight to use it so it's hard on my back. I've used straight shaft and I prefer those, Echo, Stihl, or Shindaiwa. Personally I would not start with Shindaiwa, although they are great, because they are expensive and heavy and it might be a waste if you don't have alot of customers. I have not used Kawasaki or Husqvarna yet, but I'm thinking about getting a Kawasaki.