This sort of layout was fairly common for "battlecruiser" keyboards back in the day, many of which share similar features such as a star nav and programmable keys.
To my knowledge, no-one makes keyboards with a double F bank anymore, but extra keys to the left, such as on the Logitech G11, aren't that uncommon.
The Ortek battlecruiser is a ton of fun, by the way. They're somewhat rare, and don't generally go very cheap (about $100), but they're cool and well-made boards. FORTY-****ING EIGHT F keys FTW!