I think the 2G cooler fits, but I honestly don't remember for sure. You'd have to take some measurements of the mounts to be sure if you're looking for a bolt-on - unless, of course, someone posts up with experience.
There are aftermarket coolers - but they are pretty expensive. I've read of people adapting the coolers from the oil cooled GSXR's - which have the biggest OEM coolers, but be prepared to make your own attachments and fab up hoses.