Not all of the suggestions may be right for you, but it is hoped that you find them at least helpful. If your question isn't here, try reading a closely related topic because the answer may be there. This question comes in many flavors. The available choices for Spyders span a wide spectrum. Standard M-16 grips.
P model has plastic receiver.
A model has an aluminum receiver for greater durability. Turbulence Venturi bolt. Shark-gill sight rail. External velocity dial. Camo Anodizing job.