Welcome to the forum. Glad to have you on board. You can try ipd.com or swedishpartswholesale.com or try vandsautodismantlers.com for used parts. vlvworld.com good luck, post some before and after pics if possbile.
I think it should since it is the same model. It should, and I stress should, have the same mounting points. I know that on the 850's, the GLT and the R's are basically the same with all the spoilers able to mount from the top of the line to the base model. Hope that helps.