I think that there was a post with a similar product to the IRP cooler but for a KTM 525 exc, apparently it doesnt fit. I have got a custom made PWR radiator/ oil cooler being built for me through a guy in South Australia who runs Hustler Atv. He was able to get an original KTM radiator core to them, they have designed one up which uses the original mounts and is much more efficient than the original apparently.
It should be here in a week or two and can put up a few pics if you are keen.
IRP came back to me, they have had numerous request from SX owners. They are toolimg up for development now, apparantly it will need a different oil filter which has slowed the process. End of the year, early new year is what they are advising.