I am considering a split-boom string trimmer. I need a backup for my string trimmer and I like the idea of being able to use other attachments like a hedge trimmer and possibly edger. I was considering the Echo, but I am leaning towards Shindaiwa. I am probably looking to spend under $600 on a power-head with the string trimmer and hedge trimmer attachments. Any suggestions? Please give model number(s) and estimated price if possible. THANKS!