If you attach to the rearview you will have to play around with angle or pad out one side to make sure you get the best view. I currently just remove the sucker and take the unit in with me as they can be like sat navs and the car will get broken into just to steal the camera. Depends where you live I suppose!
The cigarette lighter charger is very long and can be run round the windscreen out of sight and plugged in, but i wanted to keep it free so I am awaiting delivery of these.
Piggy back fuse
http://m.ebay.co.uk/itm/251170198363
Usb converter
http://m.ebay.co.uk/itm/251177580267
Will plug the fuse holder into a spare holder in the fuse box in the dash, like I did the btcc running lights, then wire the usb converter to it and run that either up the A pillar or along the doorseals and headlining to the rearview mirror. Whichever is easier and will last well enough