Case - http://www.amazon.com/AmazonBasics-Carrying-Case-Nintendo-3DS-Lite/dp/B0050SVPCO/ref=sr_1_1?ie=UTF8&qid=1421180847&sr=8-1&keywords=3ds xl case&pebp=1421180849457&peasin=B0050SVPCO
Rubber armor - http://www.amazon.com/Nintendo-3DS-XL-Duraflexi-Protector-Clear/dp/B00GX330XW/ref=sr_1_2?ie=UTF8&qid=1421180847&sr=8-2&keywords=3ds xl case
I use both and I've had no issues.
I like the armor as I feel it makes the XL more easier to hold.