I just converted an Echo-seems to be a great engine. Mine is a 25 or 26cc so I don't know if the crank is the same or not. The hardest part is the prop hub-I made my own on my lathe. It has 8mm crankshaft threads with a 9 degree taper. You can use the stock muffler, just braze some steel tubes in it and cover the existing outlet. I used an 11mm walbro carb and sanded out the plastic intake to 5/8 with a drum sander on a dremel (DO NOT DRILL IT!!!) I'm also using a bcma ignition, but I think he's out of stock. Here's a link to a site with ignitions. Seems to be a good deal for everything including the plug and switch harness for around $90 shipped. http://syssaaircraft.com/gas_engine_ignitions.html

Maybe someone else can point you to pre-made parts????