I don't know about any of the Chinese websites using PayPal and can understand your concern in that regard.
As an alternative, I can tell you that I used a gift card to purchase a jersey from one such website last year. I think the jersey (designed to replicate an Elite Vapor jersey sold on NFL Shop) cost about $35. I purchased a gift card worth $60 because there was no way to determine how much they'd charge for shipping, but figured that $20 would cover it. But this ensured that they didn't get my personal credit card number.
The charge on the gift card went through and there began the long wait to see if I got burned or not. TWO MONTHS LATER, I received the jersey and was pleasantly surprised at its quality. It was a knock-off to be sure, but its variations from the real ones (I counted 4) were subtle enough to pass a first and second look by most fans, I think. For the money I paid...it was worth it.
Not so sure what you might get, though, if you're looking to order one of those custom, fitted jerseys (the ones that cost $300+). Even for $100, you might not get what you're looking for.