We have additional payment module whit support for authorize.net, stripe and simple invoices for manual bank payments (cost 30 EUR).
If you are interested for this module please send me message to email: sanljiljan@geniuscript.com
Some hints to build custom payments module (not easy task, good PHP knowledge required):
You should add custom links/buttons for that payments in template files where you wish, for example:
templates\bootstrap2-responsive\myproperties.php
templates\bootstrap2-responsive\myproperties.php
Most frontend payment functionality is under application\controllers\frontend.php, search for “do_purchase”
If you need some backend changes then this should help:
And this should be surely help you: http://iwinter.com.hr/support/?p=1288