Line trimmer by Lehr,25cc Propane Powered 4-Stroke Detachable Curved-Shaft Eco Trimmer. used Propane bottles, no stale gas, no problems starting. Like the Stihl Kombi system you can use swappable tools. Such as the Ryobi tiller for $89.00
http://www.homedepot.com/p/Ryobi-Expand-It-Universal-Cultivator-String-Trimmer-Attachment-RY159