Best road bike under £1000

Hi all,

I got into cycling last year when I lost my licence for six months after ill health. I bought myself a folding bike that I could use to commute to work 12 miles each way so that if the weather was bad or I was tired I could take it on the bus. Little did I know that I would enjoy cycling so much!
I am now looking to upgrade to a road bike as I find my folding bike too slow and I want to travel further as well as taking on a cycling tour of Scotland in September this year. I have been doing quite a lot of research and I have a budget of about £1000 and this is what I am looking for in a bike.

Aluminium frame
Shimano 105 (minimum)
Good for touring, commuting and possibly sportives in the future
Comfortable ride (I’m not getting any younger!!)

I have a shortlist down to 3 at the moment (Giant Defy 0 2015, Cube Peloton SL 2015 or Cannondale Caad8 105) although I am very open to other suggestions.

Your advice would be greatly appreciated.