I've got Givis on my 08 and don't think there's any specific bashplate that is definately compatible. The horizontal bar that joins the two sides of the crashbar might be in slightly different position than the one for the Suzuki and Motech bars. It's probably a fairly easy job to get most bashplates to line up with the Givibars, but you'd have to make you own bracket. A cheap alternative to protect the oil cooler is a mudguard extenda which seems to keep most of the crap off the cooler, but obviously this wouldn't be enough if you were buying the bashplate for offroad use. I've also seen photos of bikes with cooler moved higher up and to the side, out of any harm.
I went for the Givi bars because the appear to give a bit more protection than the Suzuki ones - but some have crashed using the Suzuki one's with no harm. Didn't bother with a bashplate, since I won't be taking the Wee offroad.