I'm surprised at everybody skipping over Specialized to this point. I'm 6' 240 lbs. I've been riding a Specialized Allez Sport for a year now, and haven't had a single problem. With Specialized, you're going to get the best bang for your buck. My Bike was in the $800 price point, and came with carbon fork and seat post, as well as 105 rear deraileur. If you take a step up from mine, the Allez elite has a full 105 setup, with specialized's new pave advanced seatpost, which has an elastomer built in for a smoother ride. That falls in the $1000 range. I'm riding the original wheels that came with my bike, and haven't had a problem yet. The 105 setup would be plenty for recreational riding, and I use my current setup in Triathlon's as well, and I'm not at too much of a Bike-related disadvantage. In that price range, you'd have some room to get some accessories, aero bars (if you're going to be doing a lot of long straight riding/triathlons), a nice set of pedals (I recommend speedplay X series pedals, they are a little more expensive than some pedal systems out there, but it's what all the pro's use, and they are by far the best feel I've experienced in road pedals.) and shoes (I ride Specialized body geometry, great feeling shoes). You also could think about a nice set of Mavic Wheels, the Ksyrium line starts at about $350 for a set, and they are great wheels, plenty strong for you. I'm riding 23c tires, Which have never given me any trouble, so I wouldn't worry too much about getting 28's.
Also, don't rule out something like a Cervelo, It's the second most used bike at Ironman Hawaii, and they will have some bikes that will fall nicely in your price range with some good setups, and aero tubing. Great bikes.
Just as my personal opinion, I would avoid Crack'NFail (oops, I mean cannondale) simply because they have been teetering on the edge of extinction, and have had some quality issues in recent years. And Treks are overhyped, and overpriced (Lance Armstrong wouldn't even ride a trek in the tour until recent years, it's well known that he prefers to ride lightspeed bikes, and they paint Trek Logos on them)
Anyway, enough ranting my personal opinions, all in all, I would highly recommend a specialized, and maybe even give a cervelo a peek.