Over the past number of years, I've seen literally hundreds of people try to do this, set up businesses that accept reversible payment methods (like PayPal, Google checkout, Skrill) for irreversible Bitcoins, and it never ever ever ever worked out well for the owner. There is a reason this plugin doesn't exist and that there are no sites that offer this.

People have tried thousands of different methods to do this, sending the privkey for the bitcoins in the mail, ID verification etc etc and it NEVER worked out. Its extremely easy to purchase CC details nowadays and your site will become a target for fraudsters in a matter of hours, nevermind the fact that anyone can use their own CC and dispute the charges and win every single time.

No. converting the funds to BTC instantly won't work, how are you going to do this? even if you do manage to do this you'll see debt collectors from the payment proccessor knocking at your door looking for the money.

PS. I've previously worked for a large payment processor (not PayPal) and I can tell you straight up doing this will ruin you. You may as well just send me all your BTC for no reason, you'd probably have a better chance of getting some of it back than doing this.