Hehe, buying a new piston won't magically get rid of the PE guys ...
I like the M130 idea, which is what my MP5K runs. Somewhat necessary to overcome the loss of volume due to sorbo pad and the ultra short barrel, but also helps with preventing PE. The MP5Ks seem to come with M90 springs and the like and that's unlikely to push the piston back in time.
Now would be a good time for a neo motor if you don't have one yet, pulling an M130 at 13:1 will present some challenges.