To follow up my project of converting HPA into an ARES G36,
To answer my own question, yes it is possible although it's difficult to find Polarstar parts world wide, and long shipping times. I found the F2 engine on powair6.com and the nozzle (had to purchase nozzle and engine separately),the switchboard and reinforced hose from Amped airsoft, the FCU from Easy Airsoft.
It required a few modifications, I needed to file a tiny bit (I reckon 0.1mm) of the F2 because it was blocking the trigger mechanism, also there's a cable that has to be soldered into the switch. To plug the FCU I required to put a mini-tamiya plug for the LiPo battery. So far looks good, I also upgraded the inner barrel from a 285mm into a 455mm 6.01mm madbull, with a madbull shark hop up rubber. The inner barrel is longer than the outer barrel so I included a silencer to cover the inner.