12 tooth plates won't fit a 48 tooth basket I'm afraid.
I have the Corse slipper, as do a few others on here. It's a 12 tooth jobbie and very well made, but I *think* that it may be made by Bucci? Mine is a classic 6 ramp and ball bearing design but apparently Corse dropped the ball bearings and two ramps after that so they could put the plugs in to bump start the bikes without the clutch slipping.
I'd only get the 6 ramp and ball bearing version myself because I don't want to be pulling the clutch apart to grease the ramps regularly (lazy sod!).