This looks good. I like it, maybe bring the handgaurd back a smidge more.Something like that is doable.
Looks a little fragile though.
A rail system that attaches to the top rail like from POF or ARMS SIR may work with some sort of mount system devised to attach it near the rear of the barrel.
The stock could be done with a AK to AR stock adapter, I have measured it out some. It may take some epoxy filling and fabricating.
In the end you might end up with the something like this -
The problem with getting something that fits on an AR or any other weapon is that it may not fit on the carbine. The distace from center of barrel to top of shield is critical. Also, the distance from the front of the shield and where you want the top rail to end.Something like that is doable.