I have been using the UltiMAK M1-B Optics Mount for the AK-47 for years. It is an excellent way to mount on Aimpoint on an AK.
UltiMAK makes more than optics mounts these days. I recently came across their ACR2 Multi Rail Forend System for the AK-47. There are several rail systems available for the AK but what makes the ACR2 unique is that it extends all the way to the muzzle end of the gas block.
This extra length gives you plenty of room to run your support hand out further on the hand guard if that is the way you prefer to shoot. Some shooters feel cramped on the standard length AK hand guard. The extra length will also give you plenty of room to mount a vertical grip without interfering with your magazine changes.
The ACR2 is machined from aluminum that has been hard anodized. It features attachment points made from 4140 steel. The attachment system is so rigid that UltiMAK claims that it will allow a laser aiming device to maintain zero in field conditions.
The ACR2 is available in two configurations that accommodate milled or stamped receivers.