Those do look nice, but very expensive. A good friend of mine actually has the exact same situation, and got a local cabinet/ furniture builder to make him a nice little custom box to his specs. It came pre drilled with a vent hole on top, a compartment for his fan/ wires (which he insulated for noise), and a really cool little intake hole which closes when the fan is off. Both of the vents are hidden, so even if you look at the back you can't see! To boot, it's a gorgeous piece of furniture that blends in with his decor perfectly. The best part? For the $3000 (not sure where the pound is at these days), you could buy the custom piece, get a full climate control for it, co2, lights, fans, air scrubbers, take your wife somewhere really nice, and pay for several ounces of headstash to tide you over until it's grown!
Remember, the IDEA of growing may be acceptable to her, when she actually sees it growing, and stinking, and shining, paranoia WILL set in, and you may have a problem. Do this soooo sneaky that she doesn't even know for months, and you'll both sleep easier.