I want to emphasize how correct you are about the airsoft sights. I bought multiple airsoft replica sights and is now regretting my options after multiple dead batteries and several sights knocked out of alignment.
I personally run a Specna arms sa h23. Its essentially a Hk416. I changed the handguard to a normal 416 quad rail. An Acog replica scope (Cus drip), regular m4 stock for more battery space and random plastic suppressor i got for free from some dude who was selling some gear. I then have also spray painted the rifle with a camo paint And thats it when it comes to outside. It now weights about 3.5 kg I dont run any grips because i dont want to look like a sof operator and i think it ruins the look of my rifle. Internals have been upgraded with a new gearbox that i dont remember the name of sadly and a new Perun mosfet. These upgrades were made when the gun broke down due to a weak gearbox and mosfet. Im not fully sure if this is a thing on all of the specna arms sa h23 replicas or if i was just unlucky. Either way im quite happy about the rifle setup. The only regret i have is that i spent way too much money on different sights and other stupid shit until finding out my playstyle is more of a long range defensive role. I have some thoughts of giving it a longer barrel probably a 14.5 inch barrel because that would kind of complete the look im truly going for
