It really depends on what sort of life you expect out of your stickers, but for packaging we found 13x19 matte photo sticker paper for the i9900, but we use pigment inks, which will last longer than the dye inks that the i9900 usually uses.
You can find the sticker paper here:
InkJet Paper
Last time we tried to order the glossy, they said they didn't have it. I don't know if they have it yet.