I would recommend this case if you are looking for a case for any DS, yes it will hold the 3DS XL, which I am using it for atm.
http://www.amazon.com/AmazonBasics-Carrying-Case-Nintendo-DS-3DSNintendo/dp/B0050SVNZ8/
It has a leatherish feel, plus it's extremely solid, and will hold 3 games...