For hop up,both myself and Sp00n have gotten great results from the PDi W hold coupled with a new arm. I modded mine own in a few ways and he got a dangerwerx type B High engagement arm. His of course is much better performing because of the dangerwerx type B. I'd recommenced without a doubt these two parts. The W hold seals really well and has fantastic accuracy,very consistant hop up application. Can't personally comment on max range of the W hold since my current hop up setup is not adequate to get the most out of the W hold,I can only get 45-50m effective but this will change once I get the 3d printed stuff going.
I'd recommend thoroughly polishing the barrel,to make it smoother and reduce friction with the BB. Install the Pdi W hold and seal it with dental floss or non crack nail varnish. Install the Dangerwerx Type B arm. That should give usable performance.
For cylinder and trigger parts check out the link posted by Mike636,you can get all these parts aside from the Pdi W hold off ASPUK. You can get PDi W hold from Xfire.org from japan,costs about a tenner incl. shipping. I recommend ordering several since they only cost 3 pounds each.