you can use a sd card for games, you can use a usb stick, you can use an externall HDD, you can use even an mp3 player
just format it fat32 and copy the games like you do already with your "small stick"
i don't understand now the part you say "so i can double the use of my SD card"
if you want, you can buy a 32GB sd card and load the games from it
is better if you get an external HDD and put your games in it, if you want to make sure the drive you buy will work, get a WD my passport, this one is very popular...