That's a smartech. Personally, i wouldn't buy one.
If you get a nitro tc3, assuming you're not racing, get an 18TZ. SG Crankshaft, slide carb is my prefered engine configuration, it's very easy to install and setup. You'll most likely need a SG crank clutch nut. Those are like $2 or some poop. I think you can still get a side exhaust pullstart.
I would recommend sticking with the stock engine before you upgrade. Onroads are very easy to crash if you're not used to one. It's especially easy to crash with a high performance engine.