Hey guys, I want to short BTC but only have a coinbase account. Where can I do this with USD and a creditcard or paypal?

I've found this so far.

http://mpex.co/

https://orderbook.net/trade

https://www.bitfinex.com/

I'm not sure how long it will take to setup and whatnot. I'd like to short for a week to a month.

Thx for the help.