We generally advise companies to sell their products directly when they launch U.S. operations. It may sound easier to look for distributors, but we believe that's generally a mistake.
If the price starts above a few thousand dollars, selling your software directly to final customers will increase your understanding of why they buy (or don't buy) your products. You will fine-tune your marketing message and make the proper decisions for future releases of your products.
If you give this task to your distributors, you will never know the truth, because resellers have different challenges: They want to avoid competition from other distributors, they want to use your product as a marketing tool to sell other products, and they look for a short-term return on their investment. They seldom try to build your brand equity.
However, the distributor channel is probably the best solution to penetrate Central and South American markets.