There are many available if you have a Us corp. I put my clients at multiple if necessary. If you don't have the corp, there are other solutions, but we end up circling back to the issue of poor conversions.
Where is your customer base? I ask, because in my experience, I've run into issues with merchants that do not sell mainly in the US from their domestic processor.
This is pretty accurate. You will also need a bank account in the US as very few domestic processors will wire funds out. There are other solutions out there, but they are not cheap, and some have minimum volume requirements.