Nintendo 3DS latest system is v7.1.0-15, r4i gold 3ds work on v7.1.0-15 perfectly. the new r4i gold 3ds no need update, can work on v7.1 out of box, for old r4i gold 3ds, official released patch, you can update your card by the patch.
I'm afraid,you need another console to update your r4i gold first,otherwise,your card will be blocked forever. =( or you can buy a new card with up to date firmware,so you dont need any updating yourself, if you need,here is a store for you : http://www.modchipfactory.com/wood-r4i-gold-3ds-flash-cart-for-3ds-xl-3ds-dsi-and-ds-lite-p-1.html
so far from i read, the r4i gold 3ds card has bypassed the latest 3ds 7.1.0-15 system update directly, no update patch needed, the R4i gold 3ds rts card are pretty good and reliable, it's the best route is to go for , also make sure your card is pre-flashed, I have heard good reviews from http://www.thegamerdepot.com/buy-wood-r4i-gold-3ds-card-for-3ds-xl3dsdsids-p-150.html and got mine there.