Don't get too hung up on the weight limits listed. Those are really CYA limits. If the weight limit is listed as 300, you can bet engineering tested it safe at 400. Have a set of wheels built up and most bikes can handle a 400 lb rider. I was riding a CAAD9 at 410. I had some "big boy" wheels (Deep V, 36 spokes with White Industries Cyclocross hubs) built up for it and have had ZERO issues. That's a skinny tire road bike that won't take anything past a 25C width tire. Probably not the best choice for where I was, or even where I am (325ish), but it's the best choice for where I want to be. Wheels are going to be the weakest point of any bike for us big guys, and it's the most important part to get built right - well, that and fit.