It's recommended that you run rent a server with a reliable and fast connection. You'll need at least 16GB of RAM. Whether or not you should become a witness, refer to this post https://steemit.com/witness-category/@drakos/running-a-witness-is-it-as-easy-as-it-sounds

For voting, check my latest posts, I have updated information how to vote. Or refer to this guide https://steemit.com/witness-category/@drakos/tips-and-guidelines-voting-for-witnesses