I regret making this post
Buying a DS is not a smart idea now - the console is pretty much obsolete, so I would point you towards a 3DS. The console now has a good amount of games on it, and will be supported for a least another 4 years by Ninty. If you can afford it, get a 3DS XL. The build quality and overall comfort that you get when playing on that system is ahead of the rather uncomfortable 3DS.