What is a good claw for this game and could you help me?
The short answer is none. There are several simple alternatives to claws this year. The first is to use sprockets and either tread and flaps, or rubber bands to grab the balls. Similar to the way Crunch bots grab balls. If you must make a claw. Make sure it fits the curvature of the ball and has enough grip from rubber bands or another grippy material.
As with everyone else, I would not advise that you go with this method of manipulators. Claws have a very low capacity (meaning 1) and require more precision to grab objects.
Claws can only grab one ball meaning that it would be really annoying to have to go back and forth from obtaining balls and then scoring when you could obtain multiple, and score them more efficiently.
Arguably, claws require more precision to grab objects. With an intake, you can go towards an object and the intake can intake balls. With a claw, you need to line up the claw well to be able to grab it.