** Answer ** We recommend the standard 115/120 for several reasons. There are a bigger selection of fixtures , bulb replacement is simple , connections are more secure and the finished project is more professional looking. However , they do cost a bit more depending on the fixtures you choose , how large the system will be and you also need to be experienced in working with electricity ! If not I would not recomend doing this project yourself !! Most electrical and landscape contractors can provide this service to you. If cost is a factor , there are many great looking low voltage systems out there that are designed to be installed by the do-it-yourselfer. Thanks for The Question !