How do US companies pay for services (SaaS)?

In my case, the company’s online shop, payments – $ 80–600 per month

1. What is the most common and easy way for American companies pay for some Internet services (credit/ debit card, check, etc .; maybe there is information expressed as a percentage)?

2. My company is located in Poland. Advise which is payment solution should be connected to use the usual methods of website payment and transfer the payment directly to my bank account. Unfortunately, Stripe does not work for us yet…

3. Share your opinion on whether customers will be repelled by the fact that my company is not registered in the USA (at the same time, interaction does not imply durable and regular negotiations. A simple product for online stores)