I'm thinking to give option to payout through faucet box or xapo but I want to know is this option already exists in this script or I need to modify it?
Yes,this option already exists in this script.you will fond many payout option in this script
faucetbox,Xapo,coinbase,blockchain and bitcoined daemon too.
All you need that to read each line of config file and add your info on it sql,rewards,wallet API etc..