FYI - you can integrate it, just remember to plan on an exit strategy. Walls are easy to fill in, ie your opening should be built to enable easy full in. If I was going to buy your house it would increase the value for me...
Sounds awesome with fish room behind it. Read Serk's 300 gallon in wall reef build thread on this site, I read the whole thing on day (took me 4 hours) but it is a great resource from start to finish.
"What kind of name is Poon?"
29 gallon hex, canister filter, too much live rock, two powerheads. Tank setup June 2012. Two clowns, fire shrimp, 2 chocolate chip starfish, 3 snails