https://imin-caribbean.com/blog/st-kitts-and-nevis-taxes/

St. Kitts has great tax, but you obtain a passport by investment which requires buying a property in excess of $300K to cover a family.

Other options, like Barbados have income tax at 28%, zero CGT, but you can get tax residency by setting up a company and employing yourself. No need to buy property and no need to live there.