I've found a few unfinished Borg models over at Sectorgame, but they're rather basic.
Hey Omni, I had a cool idea for your Earth model, or basically any planet that can be modelled in this way. Have cities on the planet's surface encompassed as subsystems of the model. Then if a ship does some orbital bombardment, they can be made to target those subsystems. It'd be even cool of each city's glowmap textures would be tied into the subsystem, so that when that city is destroyed, it won't glow anymore. Combine this with a beefed up version of Bob's dammage decals (which was I think, suggested in another thread) you could also have a big scar left behind. Cool eh?
Later!