ALW
What works for one may not work for another!
Not a problem. Second hand Live Rock is the best way to go otherwise you end up paying twice as much for the same thing. a 6ft tank is about 150g (UK) or 180g (USA). You will need about 70-80kg of Live Rock, turnover we generally aim for 20x the system volume per hour. How deep a sand bed would you like, a couple of cm or a few inch? I don't mind helping you set up if you want me to?