The 12R is a great bike, dont think much changed between the 04 and 05 except for the color schemes. The bottom end torque of the 12R is indeed strong, but you'll be fine, especially since you've been riding already.
Another option to keep in mind, unless your just looking at saving money on finding a used one, is to look at the ZX14. The wheelbase is a bit longer than the 12, and it should be a more refined, more powerful bike, not to mention a tad lighter.
Regarding insurance, it's gonna be high if you ask me, since it's one of those "bullet bikes" as they say.
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"Why be you, when you can be like me. Ride a winner, ride a Kawasaki."