I'm having a 3ds XL ver. 7.1.0-16U, I like to know which card to get to play 3ds games. i saw this one: http://www.dsflashcart.com/r4i-gold-3ds-wood-r4i-3ds-flashcard-for-ds-dsi-3ds-p-248.html
far as i knew, currently, all 3ds game cards can just work on N3DS V4.1-4.5,now that your console has been updated to v7.1.0-16,i'm afraid,there havnt any cards can support running 3ds games on this latest 3ds version. All you can do is buying a flash kit play nds games or gba games. If r4i card is your favorite, then suggested you buy this card : http://www.modchipfactory.com/wood-r4i-gold-3ds-flash-cart-for-3ds-xl-3ds-dsi-and-ds-lite-p-1.html ,this is the best r4 card,uses famous wood firmware,with a regular updating and top game compatibility.
All of the working 3ds flah cards so far only work on 4.1-4.5, currently nobody has been able to get 3DS flashcarts to work on 3DS firmware beyond 4.5. Since you have updated your 3ds to the latest 7.1.0-16, I'd recommend this r4i gold 3ds rts card, http://www.r4flashcart.com/8-wood-r4i-gold-3ds-flashcart-for-3ds-xl-3ds-dsi-and-ds-lite.html it allows to play almost all ds backups on your 3ds
