StealthPay allows you to buy 0x with PayPal. Here are some easy steps to go:
1) Get a Stealth (XST) address on Bittrex.com
2) Go to www.stealthpay.com
3) Click on "Buy Stealth", fill in the relevant fields and click "Order Now".
4) In the "Payment Method" choose PayPal payment method.
5) Follow the displayed instructions.
6) After you receive your Stealth (XST), sell them on Bittrex against BTC.
7) Buy 0x.