I got a GutterVac last year, from Omnivac (cost a bit more than £499!). A good piece of equipment, once you get the hang of it. I will say that high level vaccing is a 'man's job' though. An 11 metre high, 78 metre long grainstore was too much for me, and I'm not a weak and feeble woman!
I wouldn't buy the expensive camera system though, you can make your own with a little wireless cam from Maplin's, and a 12v battery telly from a caravan. People like the camera, it's a bit of a selling point.
We made a tool out of an old garden rake, to assist with large clumps of vegetation - I don't care how strong the motors are, they can't suck up a mass of wet roots, that needs to be hoiked out manually.