Back to the question if you should get an AEG or GBBR for your use an airsoft primary. Though in all honesty, you are free to use any but sometimes there are advantages of one over the other in certain situations such as training. In this video the Recon Brothers discuss this such pointing out the differences between the two types.
BadaBingPictures got another custom gas blowback in the form of the GHK M16A4 Gas Blowback Rifle. He used the G&P WA M5 RAS Front Set and the Model Works Airsoft M16A2 Stock for the Tokyo Marui M4 MWS GBB ... "Following the M16 build I did for the Tokyo Marui M4 MWS, I soon realised that these parts also fitted the GHK M4. And so, I present to you all the GHK M16A4 GBBR."
For AK users, this custom gun made by Hephaeustus Airsoft makes it a more ambidextrous shooting platform with ambidextrous features.The grip is fitted is also fitted with the ambi-selector which according to them, would not obstruct the trigger finger for left handed shooting. Sounds good to us.