Best sporting tires you can buy today are the Michelin Pilot Powers, although I'm also hearing that the new Dunlop Q2 is an excellent tire as well. However, those are outright sporting tires.
For a Sprint ST, I am hearing that the Metzeler Z6 Interact is a top tire that is especially good in rain. Have no personal experience with it, however. Michelin Pilot Roads are also a good tire, and I had a couple sets of Bridgestone BT021s which I liked, but weren't special other than being cheap.
I'm buying my tires from Pete's Superbikes in Quebec (order from their web site) and having them installed at either Tony's or by Stan at Kal Tire. It'll cost you $60-80 to have them mounted so factor that into your cost analysis. However, in my experience, this will still save you money over buying locally.
Also consider calling The Performance Shed. They put together a pricing package for local sport riders and they're worth a call to see what they say.
By the way: we have a Facebook entry at Greater Kingston Riding Community.
