Go for the Prince2 as it will open doors and opportunities that otherwise, and needlessly, may not be available. It does provide a useful framework, and makes sure that you keep things organised in your approach to a project. However, as with many other systems and processes, it is "for the guidance of wise men, and the obedience of fools".
Is there any element of your current work, or opportunity alongside it, that could be used to give you a start in PM ?