MATE! We've got the EXACT same guitar! I love mine, and I have indeed replaced that part 3 times (i'm a bit heavy on the whammy).
If i have any advice to you, is to not get the ibanez part, it's made of a cheap metal and will chip away with use (especially if you use the ZPS). Purchase the Schaller floyd arm from Stew Mac (http://www.stewmac.com/shop/Bridges,...molo_Arms.html
It's a drop in replacement, uses stronger metals and it's a pop in arm. The only thing i liked better about the ibanez ZR arm is that the screw in style can be wrapped in plumbers tape to get an ULTRA snug fit, i'm still trying to come up with a solution for this one, but i think i'm just a bit too pedantic about my trem arm.
If you want to get the original ibanez part, contact rich (www.ibanezrules.com
), he's also a member of this site and a good bloke to deal with. If you are going to use this part, DO NOT use the ZPS, it really puts a lot of pressure on the arm socket and chips it away very quickly.
Anyway, this is a fabulous guitar, so get this part ordered and start whammying!