When we did our bathrooms at La Torre we found that Leroy Merlin (equivalent to our B&Q) have a massive range of screens and panels. We found them great for most things...bath screens, shower heads and slides,general hardware, mirrors, lights, storage boxes, garden furniture etc etc.
There is one near Ikea in Murcia Neuva Condomina retail park or the one I generally use is the one on the retail park as you approach Cartegena.... or go to www.leroymerlin.es