So the guards and the thicker clamp set turned up, it was pretty obvious from the outset it wasn't going to work out as simlply as I'd hoped. The guards (enduro acerbis) look the business and are the right size and shape, however the bar clamps don't reach out far enough to bolt onto the guards, they're about an inch shorter than they need to be. Appart from that they would've fitted in 5 mins. So, I'm in the process of trying to A. Source some longer clamps B. Find an alternative C. Get some made up.
Soon as I've got it sorted I'll let you know.