moving my 80 gal to new 220 gal - what would you do?

[surfbunny]

I am getting new 220 gal tank 72" x 24" x 30". I have some questions I am hoping you all can help me with. Some things you need to know... I have wood floors so water is a nigtmare, my current tank is on wheels which allows me to move it to get behind for the refugium and skimmer as well as water clean up when needed. This will not be possible with the new one, it is just too big. The tank sits with the back to my understair closet so I have the option of relocating my 80g to the closet (the "coat closet" will have to move) as the sump or I can put it in the base cabinet of the new tank. I am building my stand so it will be a bit taller than standard which will accomodate the 80g if I want. I would like to use the 80 gal as the sump since #1 it's free and #2 it's huge for a sump. I am hoping to be able to breed in there if possible and keep a nice collection of macro algae.

Questions: Should I put the sump under the stand or in the closet? Get a smaller sump? Any ideas for the floor?

I am planning to sift my crushed coral from the sugar sand when I set up the new tank. I have never been happy with the mix and this is my opportunity to get rid of it since I am going to have to disturb it anyway. The guys at the LFS in town both recomend a SSB and vacuuming the substrate regularly. This scares me since I have had really good luck with my DSB since I set it up 7 years ago. If I reestablish my DSB my plan was to add a small layers of sugar sand to the top of the bed over an extended period of time. I was told by one LFS to discard the bottom water left after the sifting and to start anew, but isn't this stuff that I have paid for (GARF Grunge) to get your DSB started.

Questions: Should I go with a DSB or an SSB? Maybe one in the sump and another in the display tank? Should I reintroduce the detritus filled water or trash it? Could I use the crushed coral to seed my DSB in the sump (to be removed later of course, i am thinking fine mesh tulle bags or something)?

Aquascaping questions: Should I use the PVC framing to set the base on to keep it off of the sand? I think I can manage the acrylic rods for the main shaping but how long can my rock be out of the water? Does silicone have to cure in the air or can it cure in the tank water?

My hood has 150w HQI MHs in it but the ballasts went out and are being replaced. I was thinking to get two more MHs for the 1' of space I have on either end of my hood if I mount it to the canopy in the center. I am not really interested in keeping alot of SPS corals because of their aggressive nature but I really like the way the light moves with MHs. The heat is definitely an issue as I already have a difficult time keeping my house as cool as I would like it.

What would you do if it were you?