There are only a handful of companies out there that currently produce quality electric airsoft guns with clear parts.
Those would be G&G, KWA and SRC.
If you are interested in dealing with G&G, you should contact the people over at CAS.
If you are interested in dealing with SRC I believe Ken at 007airsoft would be the first place to contact.
At this time, I believe that only AK, Armalite, MP5 and G36 variants are available.