WEX are very good, Jessops price match too, and John Lewis offer longer warranties than both as standard for extra lenses (you get 2 years on all Nikon cameras when you register it on the Nikon site).
WEX want £979 with the 18-105 and offer 12 months interest free.
Jessops want £979 with 6 months interest free
John Lewis want £979 with no interest free, but the joy of a John Lewis shopping experience if you go in store (no upselling, no crap, just what you want!)
Most important thing is to hold both, find out how to adjust aperture, shutter speed and ISO, how to switch between manual, shutter priority and aperture priority, see how each feels in the weight, the build.
If you are less worried about returns, try digitalrev who are excellent. They want £800 for the D7100 with 18-105mm kit, but it'll be a grey import. They offer a warranty service of sort but read up on it before you buy. I've used them before though and was very pleased.
Also, they have Kai Man Wong, Lok Cheung and Alamby Leung doing their videos and I quite enjoy them but Kai is an odd character so not all can stand him lol.
Their videos on the
70D vs D7100
http://youtu.be/ItEwu3dNr2I
7D vs D7100
http://youtu.be/_GWBetElHYU
Personally I prefer to pick big purchases up so that I know that I can take it back and talk to someone if I have a problem. I got my D7100 delivered from WEX as it was a insurance claim so I didn't have a choice
.
The only other things I'd suggest is downloading Lightroom from
Adobe once you have some images and a good solid few hours to learn the bare basics of Lightroom. It's a free 30 day trial and you can then buy a copy for about £60 if you shop around, or if you wanted sign up for the Adobe CC Photography offer which they just extended to the end of this month where for £105 speard over 12 months, you get Lightroom and Photoshop.
Lightroom is where you catalogue your photos, add keywords, develop them, export them to flickr or facebook or anywhere else easily.