There is a payment gateway for opencart 188.8.131.52. It should be modified to work with opencart 184.108.40.206.
4 freelancers are bidding on average $170 for this job
***** Ready to start. Please have a look at the feedback/reviews about related projects i have done here http://www.freelancer.com/users/feedback_2918828.html . Regards from Albania,Europe ******