I would get standalone. Its only the alpha at the moment, so there will be some bugs, however you'll get it at a good price, and when its fully released it may cost more, so you'll save some money by getting it now. However, in the mod there is a lot more to it (at the moment) such as vehicles, however the standalone will be added to in the future. Its really up to you, i'd watch some youtube videos comparing the two to see what you'd like better, but i prefer standalone.