How about ccbill?
If you have this adult sector on your website you only can use Payza.
Paypal, Skrill, Stripe, 2checkout and all others will close your account if users pay for adult ads.
Allmost every osclass website i see, have this personal section on his website.
And Payza is really bad company with bad support.
Offcourse you can send invoice with paypall, but for this you dont need an plugin