hey, i'm new here, so be gentle haha.

I'm planning a big road cycling trip (about 2000k's in three weeks) for next september. Six weeks ago i got a great deal on a Flat-bar road bike (an alamode FBR 1.0). I'm coming into a bit of money this christmas, and i've found someone to buy my bike, so i'm looking to upgrade.

I don't want to spend more than $1000, however i'm looking to log quite a few k's in training for my trip. At the moment i'm comfortably commuting to and from work (15 km in about forty mins) however i'd really like to step it up, increasing my output to over 50km a day.

I'm looking for a road bike, however there are so many options i'm not quite sure what to be looking for. My local bike store currently has 20% off of their giant range, making the defy 4 about $800 and the defy 3 just over the $1000 mark. Any advice on what bike to get would be greatly appreciated.