I've got the D3100 and the focus motor isn't really a factor (unless you want cheaper old lenses) and neither is the bracketing.
Its a great camera and its really easy to change the settings and just go shooting. Use the Fn button on the front for ISO and then use shutter priority or apeture priority and you are good to go.
It does everything I need.
Its down to personal preference, both a re good cameras, but I personally would go for (and did) the D3100 with this deal...
http://www.camerabox.co.uk/product....mm-VR-and-55-300-VR-Twin-Kit-&ProductID=19283
Both lenses have vibration reduction which is a big bonus (jessops model has a cheaper, poorer Tamron lens in the kit).
I looked at Sony, Canon and Nikon. I've used both Canons and Nikons on other peoples camers and personally found my way around the Nikon easier.
The jog wheel is IMO in a better place, the quick selector between single, continuos, timed and quiet is great. The LCD has loads of info for helping start and make sure you have the correct light in the picture
Both cameras are capable of great pictures, its personal preference that only you can decide on.