How to choose AC/DC adapter - high voltage low current vs low voltage high current
You have two things to consider, purchase price and efficiency. The more efficient solution will result in less power usage and possibly longer product life due to lower operating temperature. The rating of the lights may be a little deceptive. The power rating may be the maximum under any operating condition. The actual power used may be a little lower at one end or other or even in the center of the voltage range because of a variation in performance of the internal converter and efficiency at the different voltages. There is also the possibility that the light intensity may vary somewhat with input voltage.

If you care about the possible performance differences and are able to evaluate them, your evaluation can guide your choice. Otherwise you can guess about performance and choose mostly based on price.

My guess would be that higher voltage operation would result in higher efficiency.