Have you looked at something like this? Evike.com Airsoft Guns - External Parts | Evike.com Airsoft Guns - Sights | If you like those but don't want to spend that much money these are pretty much the same thing, just a cheaper knock-off of the Magpuls, but they are probably good enough for an airsoft rifle.

If neither of those were exactly what you were looking for try looking through this link and see if you find something you like. Good luck.

 

most of those looks too high. I may have to modify one for the m4 rear by decking out the rails and weld/secure it on the weaver clamp (taken from scope ring attached at the front barrel

This one i have on the way for the front. I thought it might be cool to put a carry handle on top but thats when i found out it's sitting to tall
Evike.com Airsoft Guns - External Parts | Evike.com Airsoft Guns - Sights |