i really can't recommend a perfect bike for you but i suggest riding am many bikes as you can before making your choice.
you might want to look into "century" type road bikes, giant defy, specialized roubaix, cannondale synapse, trek pilot with 25mm or larger tires on them.
i just turned 50 last month, started riding for better health 4 years ago. i started on a old steel hybrid and 15 bikes and 4 years later i ended up on a 08 specialized roubaix elite. i like the roubaix so much i just upgraded to a 2012 roubaix, i have read they much are smoother than my 08.
i am a body repair guy by trade so i bought, fixed up, test rode bikes until i found something i liked.