Rotary engines are the easiest engine to rebuild by far. Very few parts compared to a piston engine. Now for what to look for, that depends what you want. If you want anything faster than 15s get a TII. If not do not get a GXL. The base models are real light and don't have the power options(which have alot of problems). Personally I say get a TII; I had an NA then got a TII instead myself.