I have a Gen 1 MP654K and just looked online for a seal kit and got a bit overwhelmed with so many different ones to choose from so which are the best to go for as these guns are out of my field of expertise ? I also want to eventually upgrade the gun, up the power a bit but again there are several people on fleabay selling different valves so can anyone who's done the upgrade let me know which way to go please ? Final question, I have the rubber grips on my gun but would like the hard plastic ones advertised on Rusmilitary, will they bolt straight on to a gen 1 ? Sorry for all the questions and I'm guessing they've all been brought up before but did a quick search on here and tbh right now I don't have the time to read through all the pages and pages.