Having been in the acquiring industry for 20+ years and having focused on ecommerce for the last 4 years this question is very interesting.....
You say you want to obtain an ISO / Super Merchant account. This leads me to believe that you are trying to set up as a PSP, Aggregator, TPPA.
If you have your own gateway then you will also need to consider the ramifications of PCI Compliance not only for the gateway but also the users/merchants of your gateway.
Are you looking to take liability and risk and approve or decline the accounts? Delayed Funding to offset your risk? Who will provide services for back office such as chargebacks and retrievals?
Or maybe you are just looking to set up a merchant account to process transactions on a payment gateway?
The question is to broad being that our industry can go in many different directions. Feel free to set up a call and we can discuss further and get you the specific answer you seek. I think you might be trying to do Scenario #1