While it makes me sad that sportbikes cost so much for younger folks to run, I don't see why we should try and talk a guy out of a bike he clearly lusts after. Not many of us are on NC700's, so everyone draws their 'practical' line somewhere different. The R6 is one of the truly iconic bikes for a reason. If you really want a supersport, and are going in knowing the risks and costs, why not?
He's followed the rules of grouchy motorcycle forums and has ridden something a bit sedate for a few years, and is clearly willing to pay for the privilege. Fair play and good luck. I rode a ZX-10R for years, 95% on the street, and loved it. I even did shorter 4-5 day tours on it, which weren't much fun on the superslab, but it paid off in spades when arriving at the twisties. My biggest problem was fiddling with the soft luggage, to be honest.
As for the question at hand, everyone has already answered, but I'll repeat: start with a few brokers who specialise in bike stuff, like Mitchell & Whale and NFP. Once you have their best quotes as a baseline, then work your way through the rest of the non-broker lines, particularly if you have home and car insurance you can combine. I would expect you'll get your best rate from a broker, but it doesn't hurt to try everyone. I know that's not very earth shattering, but there's no secret sauce in this messed up province...
(To the OP if you do end up with a sportbike, here's my tut-tutting old fart bit: Be smart and considerate about where you speed, wear good gear (all leather and a CE2 back protector), know your roads, and learn The Pace. Ride with people better than you if you can, but never, ever with folks who give you grief if you can't keep up. Oh, and do a trackday sooner than later, even if you're worried about possibly being a bit slow. Even better, do a track school like FAST, Racer 5, Super Sonic or Pro 6. The cost is minimal compared to what you'll be paying in insurance anyway, and it'll help you get the most out of your bike...)
