it's all about the berlin method these days according to most, that is, protein skimmer, deep sand bed and live rock. i don't think you'll find anyone on this board that would recommend an undergravel filter, canister filter or wet/dry setup. my own setup (soon to be set up
) is a 150 gal with 50 gal sump/fuge, 5" DSB, berlin classic skimmer (a little underpowered, the first thing i'll be upgrading i think), and approx. 200 lbs of live rock.
if you're planning to keep hard corals or clams you'll want to reevaluate your lighting setup. my research suggests a minimum of VHO, better yet, metal halides. my tank is lit by dual 400w metal halides (one 10k, one 20k, odd i know), with 2 40w NO tubes over the fuge, running in reverse to the main tank, for pH regulation. caulerpa (macroalgae) in the fuge.