Right now i am also looking at buying a goood commercial string trimmer and edger. I don't really know what to look for that would seperate a commercial trimmer or edger compared to a non commercial. I am currently looking at husquvarna, stihl, echo, cub cadet, john deere, and toro. Which brand and model would you advise for me? What size line do you prefer, and do you use a spool or the pre-cut line? What should the recommended engine displacement be?