Ryobi has a whole range of string trimmers and edgers, both gas- and battery-powered. Which one is right for you may depend on how and where you want to use it.
Typically, when you buy a power tool, you have to buy the battery separately. Here are some Milwaukee tools where you get the ...
This Milwaukee power tool combo would normally cost almost $700—get it for $379 from The Home Depot while this deal lasts.