The theme is not encrypted and so you can definitely modify it according to your requirements including integration of other payment gateways. Implementation is just dependent upon your coding skills or you can just hire a coder to do it for you. Appthemes also have certified community partners http://www.appthemes.com/partners/ that can be contacted for customization jobs.
Please help our moderating team work more efficiently by not sending us support questions via PM. You can read more about how AppThemes support works here. However, you can send a PM to follow up and remind me if I missed your support request/thread.
