I am building my first AR upper and need some instruction and advise please? Im using an anderson upper reciecver with dust cover and forward assist already installed. I have an ESS SOCOM "16 barrel and will be adding magpul carbine handguards. What I need to know is where to locate the parts I need to finish it and need to know what torgue spec to set the barrel nut. Also, a step by step tutorial would be helpful. Also, whats the best route to go on the gas system? Standard or piston? Is piston reliable? Thanks.