Trying to transfer data from one 3ds to another.

So I want to upgrade my current 3ds to a 3ds xl because the 3ds I'm playing kills my hands (and I want a bigger screen). Anyways here's my situation:

I'm going to sell my 3ds online with the current sd card I use. On this sd card I have all my save files, luigi's mansion dark moon, animal crossing new leaf, and another small e shop game. So I'm gonna buy a new 3ds before I sell my current one. I want to move animal crossing and my save files to the new 3ds xl and leave everything else for the new owner.

Can I sell my 3ds with a couple of downloadable games on there eventhough those games are linked to my nintendo id? Do I need any special equipment to do this? Can I use my wii u to transfer stuff?

Any info is helpful. Thanks.

You can only transfer all the games. The system transfer basically moves everything to the new 3DS (you'll have to put the old SD card in the new 3DS as well). So you can't only transfer a few games. :o

You don't need any special equipment, just the two 3DSes for the transfer and internet access.

I don't know about the Wii U, sorry.