Questions about SD card: game data transferring and etc

Hi everyone. I'm not a very techie person and I feel more secure if I ask this here so sorry if this has been asked a lot of time before.

I currently have a 4gb sd card in my 3ds XL and wanting to upgrade. I found this in Amazon, can I use it for my 3ds?

http://www.amazon.com/SanDisk-Memory-Frustration-Free-Packaging--SDSDB-032G-AFFP/dp/B007JRB0RE/ref=sr_1_2?ie=UTF8&qid=1407186661&sr=8-2&keywords=SDHC+card

Or you can recommend me what brand I should get. Thank you.

Another thing, I wanted to transfer the games I had in my old sd card to the new one I'm getting. How do I do that? Will it also affect the save datas I had with my previous games I play with the cartridge? Or will that only affect the saved data I have  with the downloaded games? Thank you..

edit:

Ok I learned that I'm using and SDHC card.