Probably the biggest bang for your buck upgrade to any La Pavoni Europiccola / Professional, the single hole steam nozzle. Simple M6 acorn nut with a 1.5mm hole. The hole is small enough to create a nice jet of steam pressure in your pitcher, but large enough to not be a bottleneck. Install is easy as pie, simply unscrew the old one and then attach the single hole steam nozzle.
Made of stainless steel, polished to a mirror shine.