Re: 110cc CVT transmission cheap!
Those 110s are Chinese-made copies of Honda motorcycle engines. It's one of the most durable engines ever made and pretty much indestructible. The Chinese versions aren't up to Honda standards, but they're still very good. I've owned three of them, all trouble-free. 12V electrical, they'll power lights, signals, you name it. And yes, they will charge a battery.
They're way too big for a bike in my opinion though. Too big, too heavy and too much power, you'd end up bending the motor mounts or worse.
Attached is a photo of one of mine on a Honda CL70 motorcycle. This bike will do over 50 and of course it's much heavier than a bicycle.
Those 2-strokes are interesting too, I wonder if they'd fit one of the rear-mount friction drive kits?