I guess it depends on how much you want to shell out and where and what you bowl on.
With the IQ Tour as the benchmark ball (AWESOME choice btw !!
), you may consider the following:
Lock
IQ Nano
IQ Tour
IQ 30
Ride
My arsenal is:
Lock 1 pin down (1000 grit)
Lock 2 pin up (3000 grit)
IQ Nano pin up (4000 grit)
IQ Tour pin down (3000 grit)
IQ Tour pin up (4000 grit)
IQ 30 pin up (1500 polished)
Punch Out pin up (1500 polished)
Ride pin in palm (4000 grit)
Pitch Black (1000 grit)
That's not all I have, and I have too many as it is ... but its a expansion of what I recommended for you.