As has been pointed out already, an older road bike will probably suffice for carrying loads and touring, since it has a lot more in common with the modern touring bike than it has with the modern road racing bike. An older touring bike is an even better choice, due to the wider gearing and some other perks.

Out of the modern bikes, I think a cyclocross bike would be a good option if you don't intend to carry heavy luggage. Check out this Kona Rove you can get for less than $900 in the UK. Unfortunately, they may not have any left for sale in the US.
Another option would be a modern touring bike. While you're looking at a bit more of an investment, you need to remember that these bikes are built to last, possibly for a life time. Their frames are designed to withstand the load of heavier luggage and to accept wider tires. I'm not sure about its price, but the Surley Long Haul trucker seems to be a frequent favorite among tourers on this board.