What are your thoughts on the "endurance performance" bikes, basically more relaxed geometry carbon road bikes? I have used aero bars on bikes like this with no issues. The main thing seems to be getting them set up right so you are not reaching too far forward when in them.
http://www.giant-bicycles.com/en-us/...2/14806/66183/
http://www.feltbicycles.com/USA/2014...Series/z4.aspx
Both of these are really solid bikes on the lower end of your budget to leave room to make changes for preference items like bar/stem/saddle/wheels/etc
I personally have put some miles on the Z series Felt line and really liked it but I have never done much more than 60 miles at a time on one as it was just a demo bike.