Modifying my Cybergun MP44

[Sandman_]

Greetings, recently (about 2 weeks ago) I have found an StG44/MP44 replica from Cybergun at a great price considering that I reside in Romania (about 275 euros) and wish to disassemble it in order to replace the hop up, the barrel and potentially the motor. The issue is, I've asked in multiple other communities and the components they suggest to me are not available in my country.
If somebody is willingly going to look on these websites: Airsoft.ro, airsoft-cluj.ro, nrg.ro and 2Airsoft.ro for components that fit my V2 gearbox and are not extremely expensive (my total budget is of about 200 dollars) I would greatly appreciate the help.
What I'm trying to accomplish is getting more accuracy (I've tested bb's from .25 to .36 and I have noticed that the problem is the quality of the components). That's what I'm going for with the barrel and the hop up. With the motor, I'm going for more torque rather than speed.

Thank you in advance.