I am of similar size and would echo that the key thing that you need to budget for is handbuilt strong wheels - a minimum of 32 spokes on the back, you might get away with 28 on the front, but talk to a wheelbuilder and they will advise you. You can offset the cost of this by selling on any lightweight stock wheels that you might get with the bike you choose.
Disc brakes are a definite bonus for reduced stopping distance and speed control - if you ride in a group you will soon notice that other people don't descend quite as fast as you do ;-)
Unfortunately when you combine the above two you hit a slight snag as not many disc hubs are 11 speed compatible yet, and many of the new road bikes with disks use a mess of standards - bolt through from mountain bikes instead of quick release etc.
Do you have ambition of racing at some point or is this just general recreational riding?
If the latter I'd suggest you take a look at the GT Grade 105 models - the Alu one in particular at £1000 seems like great value to me:http://www.evanscycles.com/products/gt/ ... e-ec070839
but closer to your budget is the full carbon GT Grade 105:http://www.evanscycles.com/products/gt/ ... e-ec070837
If you get them both in for a test ride you'll be able to see and feel what difference spending the extra £1k makes - (Fully hydraulic brakes and full carbon frame in this case).
By getting an adventure/cyclocross type bike you're going to be getting something with a bit more strength built in, whereas if you go for a full on race spec machine the risk is that some of the components might be found wanting. I can assure you (as someone with both a heavier disc equipped bike and a racier carbon fibre one) that in the real world you'll see very little difference in speed.
what about the frame size ? and Wheel size ? should i get a bike fitting ? does anyone know a good bike fitter ?
Always interested in the "didn't bother with stronger wheels" thing. When I started riding road bikes I was 115kg and took no notice either. All was fine initially and then as I got fitter (and lighter) and started really generating much more power (standing up on pedals on some hill sections etc.) instead of just spinning gently I started to find spokes popping and wheels deforming (the dreaded brake block rub and even the chainstay in one instance). So despite being lighter I went to a handbuilt option and haven't had any problems since. There is also the added advantage that my handbuilts are stronger for the same weight as the factory options were.