I would like to install ArduCopter and use it on a drone. Never used it before and I am wondering what is the best hardware to buy to install it on? Or the pros and cons of different options. Any advice or linkswould be great thanks.
The best? Do you mean the most expensive?
Hex Cube Blue, CUAV X7, Mro Control Zero, HolyBro Durandal. Start there. For boards <$100 there are many.
you can look for the mRo pixracer pro… its a very good size board with H7 mcu, easy to set.
Aside flight controller you need pdb… gps module… etc.