We have some glossy curves available (which are custom curves we've made over the years for different customers, and have been confirmed to work well before making available for others to use), here: http://www.inkjetmall.com/tech/content.php?158-Piezography-K7-Additional-Curve-Resource
This page includes information about what printer models can use the same curves, and how to install new curves. 8-color K3 printer models should use "3800/3880" glossy curves for the best results, as these curves have a slightly lower ink limit for optimal gloss compatibility. The 3800/3880 MPS curve download does include a few curves for Canson Platine Fibre Rag, but not Photo Rag Pearl, though you can try the Photo Rag Pearl curve in the 4800 or 7800/9800 folders (but these have high ink limits, so may not produce as good of results as the 38xx curves). If you'd like, we can certainly make custom curves specific to your exact printer, ink, paper and computer setup, which will give you the very best results for your system.
I hope this helps, best regards and happy printing~ Dana