I dont think Sorbo Pad's will fit on a Systema Silent Head Set cylinder head do to it being defernt then the commen stock cylinder head's we all love and know. Me myself I would not go any higher then a m120 spring going higher then that your going to run in to having to do more upgradeing of part's to handle the heaver spring.
I think you can go for this set up. But Im far from a expert on this stuff.
http://www.airsoftparts.ca/store2/in...oducts_id=1023
http://www.airsoftparts.ca/store2/in...oducts_id=1184
http://www.airsoftparts.ca/store2/in...roducts_id=771
http://www.airsoftparts.ca/store2/in...roducts_id=759
http://www.airsoftparts.ca/store2/in...roducts_id=887
http://www.airsoftparts.ca/store2/in...roducts_id=299
http://www.airsoftparts.ca/store2/in...roducts_id=903