If you are a US Citizen you already have the right citizenship. You need to make PR your full time residence (over 183 days a year). Then under the laws (unless changed in the future should the US Congress notice this amazing tax break) your interest income, dividend income and capital gains are tax free. If you business is a service business that can be conducted from Puerto Rico you can pay a 4% tax on your corporate net profit and the dividends from that corporation are tax free.
You can do all of this without surrendering your US Citizenship or getting a special visa. Puerto Rico is a great tropical place to live and not that far from the USA.
Read more about the benefits in Forbes Article. http://www.forbes.com/sites/janetnovack/2015/01/27/puerto-rico-expands-tax-haven-deal-for-americans-to-its-own-emigrants/