Gameshark Version for US V4?

What version of Gameshark is required to be able to play PS2 CDR backups and DVDR backups on a US V4 with a Neo 2.5 DVD key chip? I've noticed some at stores that have little round V1.8 or V1.9 stickers on the back down near the barcode. Will I see a V1.9x sticker or will all V1.9x just have the V1.9 sticker? If so and I need a specific version such as V1.91, how would I tell w/o buying it and checking the disc? Is there a way to get a specific version disc from anywhere?