Originally I wanted a (6-7-8 foot)x2x2 tank but now I'm leaning towards a 60"x30" - probably 24"tall GLASS tank. (I am sooooo over cleaning the inside of my acrylic tanks!) Don't remember who it was, but someone posted pics of their build and it was a 30" tank - looked pretty awesome to me. Since my arms aren't that long, a 24" tall and 30" deep should still allow me to reach most of the back-bottom of the tank to decorate and reconstruct. Standard equipment will be used and some of it I'm already stockpiling : cone skimmer (in use), Neptune Apex controller (scheduled to arrive 12/28), coral frags in the frag tank, Drews dosing pumps. But what I plan for lighting is still in the 'to expensive to buy now' stage - I want an LED light that will completely light up a 30x30 half of the tank, like T5's or MH's light up my tank now. Several dealers have units that look promising, but at $850 EACH, it's going to be awhile before they hit my doorstep :-)
Depending on the layout of the house (this is my retirement tank for after we move), I want the maintenance items to be in a large sump in another room. Planning for that will come after we decide on a house. NINE MORE MONTHS !!!! :-)))