usually they require real crypto to communicate with their apis, and the apis tend to have multiple steps in order to avoid the client storing sensitive financial information

most of the time, the payment provider has a sdk module which simplifies communication with the api due to the complexity

the sdks tend to be focused on use in a webstore, so your question comes down to how do you want to integrate it with netsuite, and how much like a webstore that integration is

it might be possible to make your integration act like NetSuite's internal credit card integrations, but you will have to look much closer at their api to determine if its feasible