If you go to Lowes web site look for the cheap Bolins weedeater. The name has changed but the engine is still a Ryobi. The Homelites are my engine of choice & if you want to spend the extra $$ get the cheapest John Deere weedeater at Home Depot. They are 30cc Homelite engines instead of the 25cc in the Homelite brand name. Either engine will allow for basic aerobatics but for 3D your barking up the wrong tree.

Good Luck
Steve