Just get the Sony one, at least you know then that it'll fit & be fully compatible with any current & future online games, unlike some other 3rd party ones that are on the market.
Plus you'll get full support from Sony if anything goes wrong.
Best Source For Your PS2 Needs. Always
first with new PS2 DNA$ Disc IDs - Be 1st to get your backups online!
Our Latest IDs: Test Drive Unlimited(PAL), Snooker 2007(PAL), UEFA Champ League 2006-07(PAL), MVP 07 NCAA Baseball(US), CollegeHoops2K7(US), ArenaFootball:RoadToGlory(US)