Originally Posted by Cycle Tourist

Jethin has a point. Whatever money you spend on a "racing" frame will never make much of a difference. Short chainstays and wheelbase and an upright geometry will do you in.
Turning a hybrid or sport bike into a tourer will be much easier, cheaper and more satisfying in the long run. Wider tires and a longer wheelbase will give you the comfort you crave. Here's a used Nashbar hybrid conversion that ended up costing a couple hundred.(minus the saddle).