A solo 401(k) can be a great choice for the self-employed, offering high contribution limits and both pre-tax and Roth options. The main benefits are flexibility in contributions and potential for significant tax savings. The setup can be a bit complex, especially if you're unfamiliar with retirement accounts, but providers like Fidelity or Vanguard have good support and resources. Choosing a provider often depends on fees and investment options. The Roth option is beneficial if you expect to be in a higher tax bracket in retirement, providing tax-free withdrawals. For managing contributions and investments, consider automating contributions and diversifying your investments to balance risk and growth. Always review your plan periodically to align it with your financial goals.