Recommendation for visa agencies

I'm looking to pay an agency to get a Q2 visa. The first "local" agency I came across on google is in Orlando (2 hours away), who said you'd go in their office to submit material after submitting online info, which sounds odd to me. The point of an agency is to mail everything in so I don't have to go anywhere in person.

Can anyone recommend a good agency they have used for Q2 visa? I live in Florida if that matters (though I don't think it should matter as long as that agency goes to DC embassy). Thanks in advance