After some research it seems that the QingQi 200cc bike is the most reliable, does this still hold true?

I am planning a trip from Chile to the USA, is the QingQi likely to last 20,000km+? I read the valve clearance tutorial, it doesn't seem so bad. The bike which I require must be cheap (the $AUD has just suffered a massive fall against the $USD), reliable and can go off-road, do you think I would be crazy to try this trip on a CN bike?