Was the rear bearing for me. Had it happen at around the same speeds as above and then it started at 70, 65, 60 and so on.
As for the rear discs C2kev you will be hard pushed to beat Wests Renault (iirc) prices off here. I had mine replaced a few months back and after calling all the normal places and checking on eBay his prices pissed all over them. They also are official Renault bearings so although they are still made from cheese they are a lot better than some of the ones you can buy that are pressed in. Also come with new ABS rings which a lot of the none Renault ones don't do.