A standard sink base is 36". You'd have to rip out your cabinets or greatly modify them to be able to put in a 5 1/2 foot sink. Conventional cabinets aren't made to support something so large. That would void the warranty on the cabinets and leave a great deal of the structural integrity of the kitchen up to a carpenter. A carpenter that may or may not understand how much weight a big old sink full of water can have.

Or is this just SPAM?

Found a previous discussion on this sink (ignore the spamming from the Galley folks in the thread). I think it's a really cool looking, functional sink - that and Kohler Stages sinks - but personally I can't give up that much space for a sink in my kitchen. If you have the room and do a lot of cooking, it'd be tempting....

Here is a link that might be useful: Galley Sink thread