Be aware that you WILL have to drill holes to install Sperzels. *(I just had to do this to my PRS!) *Most tuners use a small screw on the bottom corner of each tuner to keep the tuner from rotating. *Sperzels use a little pin to do the same thing, but it's at the top of the tuner. *You have to drill a hole for that pin to install them, and the hole from the screws on your old tuners will show.
I have a guitar with the Gotoh locking tuners. *I prefer Sperzels for their ease of use, but the Gotoh ones work just fine. *I think the Gotohs would be your best bet. *I've never seen them for sale seprately though. *I don't think Ibanez is still using these on any of their guitars, but you might be able to order them as a replacement part from an
Ibanez dealer. *But a left-handed set in cosmo black might be really hard to come by...