No it won't be. I have the 120watt Razor on my 38gal Innovative-Marine cube. You'll need that size. I put the Nano on my Innovative-Marine 16 gal and it lights that fine.
Do you have a realistic date on when the fish room will be opening. I've been hearing "soon" since the store opened. I've cycled and stocked one tank since then and am currently cycling another tank which I'll be stocking in the next couple weeks.
I wouldn't pull any glass out of the back. Start with measuring the media basket and chamber to make sure they're within spec. In Tank shows the media basket fitting from the photos on their site.
On my 38 I have the Protein Skimmer in the first chamber with a piece of blue filter pad to pickup...
I wanted to go with a deep sand bed. The amount of live rock I put in with the sand and another 25 lbs of dry rock did the trick. The bacteria will start to populate the dry rock in no time. I also used the "ghost" feeding method. I fed the tank as though there were fish in there so the bacteria...
I started my 38 Nuvo with 60 lbs live sand and 25 lbs live rock. I put an Hydor Slim Skim Nano skimmer in my Nuvo 38 and the In Tank replacement basket in the other chamber. The In Tank is what the Nuvo really should come with, not the cheap ones that come with the tank. I'm using a similar mix...